One advantage of erasing a mechanism that essentially requires Marvel’s flagship character to only be romantically involved with one woman is that you’ll have different storytelling possibilities with other characters. A romantic triangle between Spider-Man, the Black Cat and Daredevil, will be different from one involving Carlie Cooper, or Mary Jane Watson. In a post on the Comic Book Resources Spider-Man forum, Kurt Busiek (Untold Tales of Spider-Man) opined
I have to admit, my interest isn’t in Peter finding the right girl, but in being entertaining. If being miserable makes him entertaining, then maybe he should meet the wrong girls.
I’m one of the Vicious Cabal that thinks the marriage should never have happened. I thought Gwen was kind of a drip — very sweet and lovable and passive, when she wasn’t irrationally jealous or angry about something. She’d probably have made Peter an excellent wife, but the result wouldn’t have been exciting, which is why John Romita thought it would be a good idea to kill her off — she makes a much better “ideal girl lost forever” than she does an active player in an ensemble cast. I liked MJ when she was an overcaffeinated hipster, and lost a lot of interest in her when she turned out to be a product of a broken, abusive home, and under the “laughing on the outside” exterior was a sad, wounded moper like so much of the rest of the cast — Peter, MJ, Flash, Betty, Liz, Harry…sometimes it seems like everyone in the cast is from a damaged background. Still, she had more drive to do her own thing than Gwen did, and that made for better drama.
But I don’t think Spider-Man needs a Lois Lane — there are enough comics characters with one great love already. I’d be fascinated if he had several major romantic foils, the way Milt Caniff did with Pat Ryan in the old TERRY AND THE PIRATE comic strip. Pat pined after Normandie Drake, lusted after Burma and was intellectually challenged by the Dragon Lady, striking dramatic and romantic sparks with each of them that illuminated his character in different ways, with others that cropped up when they were offstage. Readers argued over which of the three would be the best for Pat to end up with, and there were good cases to be made all around.
I like Peter’s life hectic, where he has to juggle lots of responsibilities, so I’m for there being multiple characters who he strikes sparks with, and different reasons each of them might be a good idea. For instance, I don’t think in a million years he should “end up” with Felicia Hardy, but I think things are often more fun when she’s around.
So I say mix it up, pull him in different directions, but do it with characters with vivid, compelling personalities who each have their own strengths and weaknesses to offer.
This applies to existing characters, as well as new ones. Once writers come up with more details about possible romantic interests, new story ideas will open up for them. You could do something with Peter dating a woman in her mid-twenties who has custody of her 11 year old brother, after the tragic death of their parents seven months earlier. In that case, Peter finds himself in the awkward position of potentially costing his girlfriend custody in any dispute.
You could do a story where Peter likes a girl who learns that he’s Spider Man and cuts off all contact with him, because she’s afraid that his hobby may put her and everyone she loves in danger. Then you’d have the material of a heartbroken Peter wondering if she’s right, as he can’t argue when says that she doesn’t want the possibility that the Hobgoblin will endanger her nephews to get to him.
You could have a story with Spider Man getting involved with the Israeli superhero Sabra. When the news gets out, Spider Man could find himself a tabloid fixture and Sabra’s superiors might get pissed. Marvel could also use the opportunity to introduce her supporting cast and archenemies, and you could get a fun story out of her enemies targeting Spider Man, twisting gender stereotypes while introducing potentially recurring villains.
These stories and their effects wouldn’t be limited to the Spider Man books. Spidey dating a fellow Avenger may add to tension in that title, especially in the aftermath of a break up, as others are affected by the relationship. The same could be said if there’s simply romantic tension between Spider Man and a female Avenger. The Spider Man dating a superhero plot could involve Peter dating a known figure usually not associated with Spider Man (ie- Sharon Carter, etc) which might upset some individuals connected to her. How would Cyclops react if Peter started dating Rachel Grey? In the process, Marvel would create new links between major properties, something that can inform interactions between the characters decades later. Ultimate Spider-Man’s relationship with Kitty Pryde didn’t last long, but it had major ramifications years later.
Peter’s relationship with Carlie Cooper—his last in the regular comics—offered something new. Spider-Man was one of her best friends. Her job often put her into Spider-Man’s world, and there was the chance, that should she learn Spider-Man’s secret identity, she would be able to interact with him more comfortably than the others. But, there remained the possibility of conflict, considering the unique professional risks, the potential for philosophical differences between a cop and a vigilante and the difficulty in bullshitting someone whose job it is to be familiar with murders. When they eventually broke up, Carlie Cooper became a new type of ex-girlfriend for the wallcrawler.
There’s also always the potential for Mary Jane or Liz Allen to cause all sorts of complications, in addition to any new characters. So far, I’ve been talking about the stories you only get when Peter Parker is dating someone other than MJ. But the new material is not limited to that.
What Would Spidey Do? 
Goood blog post