In this case, "conformity" applies to the everyone who lives in the real world. As little as people in this world can find to agree universally upon, we seem to have all come to the conclusion that running around at night in tights looking to engage armed, hardened criminals in fisticuffs would be such an extremely stupid thing to do, that somebody who did manage to get caught at it before getting himself killed probably would wind up getting some state-sponsored psychiatric care.
For most people, sure. But that ignores the possibility of extraordinary people -- people who find ways to succeed at things that most people would never dare try. Isn't that what most fictional heroes are, in any reality? You could say the same about someone who tries to fight spies with a roll of duct tape and a pocketknife, but MacGyver pulled it off. And most lawyers would be crazy to try to get their clients off by exposing the real killer in the preliminary hearing, but Perry Mason did it every week. Fictional heroes are usually people gifted enough to change the rules.
Besides, by now we've seen plenty of superhero adaptations that devoted a lot of time to explaining why it could be rational for their heroes to use the methods they employ -- Batman Begins being a leading example. Nolan's Bruce didn't become Batman because he was crazy, but because he made a calculated choice to employ theatricality and symbolism as a form of psychological warfare against the underworld, and because he had the training, resources, and technical support to do it with a degree of effectiveness and safety that some random wannabe wouldn't be able to achieve. The TV Flash doesn't wear a costume because he's got a fetish, but because it protects him from the effects of his speed. And so forth. Screen adaptations of superhero stories have found many ways to justify the costumes and methods of the heroes for a "real-world" setting, so the old "You'd have to be crazy" meme is just ignoring all the precedents.