While the illusion of change approach works well with a flexible status quo in which things can change from story to story, it doesn’t really accommodate a stable state of affairs. That represented one of the problems with the spider-marriage.
Marriage removed tension from the series, because readers knew that the relationship will survive conflicts. It also produced stability, as it was difficult to repeatedly convince readers that Peter may not have a loving supportive wife to go home to. If “growth” isn’t an option but you want to keep the marriage, this means that the comics would have to deal with an eternally childless married couple in their late twenties. If Peter and Mary Jane have a child or find Baby May, that kid’s age will have to remain the same, which makes Peter’s adventures seem more inconsequential, although The Simpsons and Family Guy have conditioned readers to not ask questions about why cartoon babies don’t get older.
There are a few problems with these approaches, beginning with the way it seems to freeze the status quo, as you know that no matter what happens, Peter will eventually be comfortable in his house with his beautiful and supportive wife. A writer can’t end a story with a married Peter Parker miserable and alone, wondering if that’s ever going to change, without doing something bad to Mary Jane. And most of Spider Man’s problems are somehow less significant when he had a beautiful, loving, understanding and supportive wife who he can really confide in. This limited the drama and made him seem like a jerk any time he complained about his life. It also limited the directions the writers can take the story in.
As there will be multiple issues of Spider Man a month for the foreseeable future, the writers and editors do have to come up with the best status quo to keep all those books interesting and compelling in the years and decades to come. Fans of the marriage will maintain that any problems with making that status quo indefinitely compelling are purely the fault of the writer, leading to the “good writers” argument. I would suggest however that a perpetually childless couple eternally in their late 20s will become uninteresting faster than a single guy eternally in his late 20s, due to the greater variety of the latter. Peter’s life shouldn’t always be miserable, but it’s far more interesting when it’s not stable.
These are the reasons why it seems that the majority of potential writers prefer Peter Parker being single, a decision that has little to do with their assessment of their own talent. Some married readers may laugh at the idea that marriage brings stability, but for storytelling purposes, it ultimately does when compared to the alternative. Ask any religious leader or politician trying to protect the institution. That type of stability is good in real life, but bad in an ongoing drama, where it freezes the status quo (especially if the couple won’t significantly age, have children or treat one another badly) and makes it harder for readers to believe that any developments (Mary Jane believed dead, Mary Jane goes to California) ultimately matter. Changes to an unmarried Peter Parker would matter, as readers can believe that an argument can lead to a break up and that the break up will be permanent. with potential consequences decades later. This will be more effective if the writers can make any new romantic interests as compelling as Mary Jane.
Given how strong Peter and MJ’s relationship has been, and the iconic status of both characters, it was difficult for writers to create problems in the relationship without making one (or both) seem unlikable. Mary Jane has the patience of a saint, so Peter can’t really be pissed at her, unless she were to do astoundingly stupid, and probably uncharacteristic. Peter Parker’s unreliable because of his day job, where he has objectively saved more than ten thousand people. At the same time, Mary Jane should know by now what she’s been getting into, so she can’t really be mad at the guy considering all the lives he saves. It is possible to have a conflict between the two, while making both sympathetic. But it’s difficult. And it’s a story point that would be repeated quite often, even if the ending is always the same.
A counter-argument is that not allowing marriage is also a stabilizing force, but there’s more variety with that edict. Peter dealing with the aftermath of a kiss from his best friend’s girl (whom he considers to be ridiculously attractive) is different from Peter dealing with the aftermath of a one-night stand with his roommate, which is different from Peter having a friends & benefits relationship with an ex who doesn’t really love him, which is different from Peter slowly beginning a relationship with someone in his social circle. And so far, these stories involve four different romantic interests.
In terms of stability, the spider-marriage was equivalent to restricting Peter to one residence (one house in New York City) or one job (with a particular employer) in a permanent manner. There can be significant conflict, but the writers would be greatly handicapped. That said, just as there’s no rule saying that Peter Parker always has to work for J Jonah Jameson at the Daily Bugle, there’s no rule saying that he always has to be a photographer. JMS made him a High School Science teacher, followed by a job with Tony Stark. Guggenheim gave him a low-paying job in a comic book store. Zeb Wells had him take a taxi-driving exam. Mark Waid blacklisted him. He’s also been outside of New York City, getting involved in an alien civil war with the Fantastic Four or fighting for his life in Boston. Future writers aren’t also restricted from taking him out of the city.
Some have asked whether there’s anything wrong with Peter having this one win. The problem with that argument is that the marriage represents more than just a single good moment. It is perpetual happiness, which doesn’t work as well in a serial that’s mean to continue for decades, especially if it’s about a character whose initial appeal was his private problems, as well as unique (and amazing) superhero action sequences. Conflict is necessary for that, but it’s difficult when the marriage eliminates much of that.
I would not claim that the marriage is permanent happiness. But when Peter Parker’s married and things are going well, he’s happier than he would be if he were single, because he has a loving, supportive and beautiful wife at his side. When things are going badly, he’s still going to be doing better than he would when things are going badly and he’s single.
The hero riding into the sunset with the girl is a lovely ending. The hero becoming a stronger man thanks to the support of his wife is a good way to begin the third and final act of a storyline. However, Marvel and DC Universe comic books are unique as they’re telling stories with no ending in sight, which represents a problem with traditional storytelling conventions (IE writers can’t provide a definitive conclusion). It’s worth remembering that whenever writers change an aspect of the status quo or resolve a romantic triangle that had been a part of a book for years, they still have a few decades left to that story (although when Peter and MJ got married, there really wasn’t a resolution to any love triangle or long term storyline.) The guy getting the girl is usually the ending to a tale, not the basis for hundreds of future stories, which is a major thing to keep in mind when calculating what is best for the series in the long term.
I am unaware of a single work that has maintained a consistently high quality over the course of several decades, while focusing on a married couple who have no children (and will have none over the course of the series), and always remain the same age. I can think of a series that has maintained consistent quality following a bachelor over the course of a few decades. While the writers will be able to provide tension between a married couple for a while, I doubt their ability to keep it up for the next twenty five years, especially if the Parkers remain eternally childless and in their twenties.
Earlier I noted that there are some advantages to having one element of the status quo anchored in a particular way. Other elements of his life (where he lives, where he works, what the supporting cast is up to) aren’t stable, so the writers could explore those avenues. But there is a significant restriction when the juggler suddenly has one less ball to play with.