Comic books and movies are two different media. I could complain that comic books don't move enough and have no sound tracks, therefore are less immersive and compelling. But I don't, because comparing across media is not fair. It's apples and oranges.
Bright colors work on a comic's page, but not so well in movies. Who dresses in bright primary colors on a daily basis (without being an object of ridicule)? Movies of late are simply trying to hew more closely to reality, and in a story that is closer to (but not exactly) reality, most superheroes wouldn't have the means or motive to maintain a bright spandex "super-suit" as their costume. Can you imagine the athlete's foot that would develop when sweating in a body-sock while fighting super-criminals? Spidey would be laid up for a week recovering after each battle from the crotch-rot alone!
What's so great about being superhuman? it's a weighty responsibility, causes isolation from others, and I don't think I'd trust someone who didn't feel a little bit of anxiety when they have that much power at their disposal. Those kinds of people would end up as villains - the Red Skull, the Green Goblin, etc, really enjoyed their superpowers, but didn't care about the human part of being superhuman.
Given the change in story-telling medium, naturally different elements of the story have to be emphasized. Hulk was a great translation of a comic to film, but it was too good a translation. Few people want a literal comic book on the screen, where most of the story is still imagery or multiple overlapping panes. The only reason to change a story's medium is to use the strengths of the new medium. There's a reason Ang Lee's Hulk got a soft-reboot. The idea was sound, the execution was wrong.
I think gender-swapping is an interesting way to explore the heart of a character - what is it about Superman/Batman/Spider-man that makes them who they are? Their genitals? Hardly! Though I think in Man of Steel that Jenny was not intended to be Jimmy Olsen, but a different character altogether.
I'm a fan of the Dune series of books (the works of Frank Herbert only - I've not read the extensions of the canon by KJA and Brian Herbert) - but most of the time the story doesn't translate well to the screen. That's just due to the nature of the story, though. Dune on screen isn't necessarily bad, just not complete compared to the novels. Making a movie of Dune isn't disrespectful of the novel, though, no matter how poorly executed. Who would take the time to make a movie of a story they didn't like? What kind of unbalanced personality would put the time and effort into filming a story they disrespected? I'm sure Nolan absolutely hated Batman, which is why he devoted years of work to make those three movies. Even if it were done out of hate rather than love, the translation doesn't destroy the original.
In sum, comic book movies are movies not comic books. Appreciate them for what they are, rather than hate them for what they're not, were never intended to be and simply can't be - comic books.