The cinema is £60 a pop, minimum, for me and the OH. That's a pervasive fee for generic cinema going and it means the spectacle better be worth it, otherwise I'll watch from the comfort of my own home, thank you very much!
I don't watch DC films in the cinema because they're terrible, but Marvel is an automatic trip for me, as are any other films across any genre where I feel the experience will be enhanced because of the cinematic surroundings.
The proliferation of superhero films is not to blame for the decline of the industry as great indy films and small budget productions get more exposure than ever if they are good, and there are enough people who abstain from the genre (It's not a fad) but do nothing to fill the gap to state that something else is happening. The combination of expense and the home cinema experience being preferable altogether for some, has more to answer for.
DC's films tank yet they want to make more than ever before, so there's more to it than money makes money and I'll maintain that the superhero genre will be established in its own right rather than go away. What people who slam these films as generic tosh tend to omit is that the material these movies are made from is as old as their grandparents in some instances and for many others has always had a legitimate place alongside other forms of entertainment. Just because the medium has changed to the big screen, it doesn't mean the genre has any less of place nor a lack of material to be dismissed as a fad, which some seem to be claiming it is. If anything, these movies can just pick from their extensive source material and grow as long as the content remains up to par (Marvel) and we'll see where DC end up after their next attempts to strike gold.
As for these films taking away from other projects, they seem to run concurrently with little bother? Star Wars, Jurassic whatever, Avatars, Mission Impossible, Fantastic Beasts etc get made and new IPs are reliant on directors and the stars attached to them and it would be ridiculous to say the superhero genre has the monopoly on either.