When “civilians” imagine how typical comic book villains act, they’ll generally think of DC bad guys. These are all the Batman enemies with built-in weaknesses (Riddler’s desire to leave clues, Two-Face’s reliance on his coins), the mad scientists who Superman beats up, or the Flash Rogues who just love hanging out together.
Marvel’s bad guys usually have something closer to real world motivations. Spider-Man and Daredevil tend to fight criminals who just happen to have super-powers, and use those to obtain a combination of money, power or revenge. The Fantastic Four often fight evil kings (the Skrull Emperor, Namor, the Mole Man, the Kree Supreme Intelligence, Annihilus, Doctor Doom). And the X-Men fight terrorists, either mutant supremacists like Magneto, or bigots like the Human Liberation Front.
To some degree, this ties into the idea that the Marvel Universe is supposed to represent the world outside your window. In that case, it makes sense for many of the bad guys to have real world counterparts, even if real bank robbers aren’t as daring as the typical Spider-Man bad guy.
By this reckoning, the current and best version of Lex Luthor, the billionaire scientist warped by his jealousy of Superman, may be DC’s most Marvel-like villain. It’s worth noting that the character has changed significantly since his debut in 1940, when he was a generic mad scientist. The current incarnation didn’t exist until the 1980s, developed by two writers (Marv Wolfman and John Byrne) who had done extensive work for Marvel.
DC’s patchwork format is somewhat responsible for the differences in attitudes, as is the incredible debt Marvel owes to one guy. Subsequent writers would all build on Stan Lee’s approach to superhero comics. And because most great Marvel stories exist within a shared universe, there’s a consistency to how writers handle the antagonists.
As the DC Universe is composed of so many disparate parts and revised so often, there’s slightly less of a core identity. The depictions of particular villains can change rapidly, with Penguin going from bird-loving thief to disreputable night-club owner, as the Joker went from a mass-murderer to prankster, and back again. With all the revamps, writers tend to stick with more iconic themes, often going with what the public is already familiar with. Even if someone wanted to push the DC Universe in a particular direction, subsequent writers and editors could take everything back to basics. If the writers on all the self-contained titles weren’t already doing it.