I feel these films can be 'gritty' and still retain a audience pleasing sense of humour. The Nolan films are seen as extremely gritty but still have some pretty funny moments.
Even the Marvel films are not non stop hijinks with the exception of GoTG which had a bit too much of that for my tastes.
The problem is people turned it into a binary choice. Somehow the conversation shifted to "superhero movies need to be happy and cheery cause that's how the comics are" or "superhero movies need to be grounded and serious cause that's the only way they translate to live action."
The problem with both views is that they ignore history. Superhero comics have had every tone under the sun. Just look at the two characters in this movie; Batman and Superman have been serious, light, funny, ironic, dark, gritty, and everything in between. The same can be said of many other DC characters and Marvel characters. People implying there is one "superhero comic" tone often come across like they've never actually read a comic book.
As for the serious argument, the whole idea that there was this big trend of super serious comic book movies is largely a fabrication. Look at the whole history of superhero movies and there have always been lighter movies and more serious ones. The original Superman movies were followed by the darker Swamp Thing and Burton's Batman, which walked a nice line. The rather dark Blade and more serious X-Men came about the same time as Raimi's Spider-Man. The original Fantastic Four came out the same year as Batman Begins; Iron Man the same year as The Dark Knight. There was never some oppressive period where people were removing all the "color" from these films.
For DC in particular, people seem to really want to ignore the lighter films they've done. Green Lantern, Superman Returns, Catwoman, and the Schumacher Batman films were good movies by any stretch, but they do stand as a sign that WB is willing to try lighter stuff when a situation calls for it.
