The thing with realism is a tough balance. Perhaps the success of comic book films has exacerbated that demand or expectation from some for "realism". Whereas longtime comic book fans have long accepted the fantastical, and at times downright silly, aspects in comics, I have to wonder if this desire to appeal to the broadest audience possible (the "normies" as some call them), Hollywood has been trying to make things all 'work' in a real world to get "regular" people to be better able to buy into the stories and characters. Sometimes I think that's been pretty cool, but at other times (like with the ugly designs of the Nolan films) it's went overboard. I do think we need to have that space for the fantastical in comics. If we take that away, then we'll be losing something.
Though from the very beginning, heck, even predating comics, there were violent pulp characters/stories, and that carried over into comics. Also, there have long been salacious comics. As for the mainstream, we saw more acceptance of darker themes in the 80s with the embrace of Frank Miller and Alan Moore, among others, and then people went ham in the 1990s with blood, gore, and skin, and while not all of that was realistic, and some quite fantastical, it still fed a desire, while also creating or mainstreaming one that that kind of content was cool and desired (much like how kids wanted the music with the Parental Advisory sticker on it back in the day).
I thought what RJ wrote about the big 2 making comic stories plausible within their own universes was a very good point. I hadn't considered it like that before and it works for me.