I mean, I like 'em when they're GOOD - like most of the MCU, and the Dark Knight trilogy, and some of the X-men films (and I haven't watched the old Spiderman films in YEARS, but I remember liking them too). 'Captain America: Civil War', for example, was one of the best films I've seen in the last few years, in ANY genre. And hell, in a lot of ways, the Buffyverse is a superhero universe like Marvel and DC, and we all love it, right?
I think it's not such a weird phenomenon. People always wanted stories about larger-than-life heroes, and they always got them - mythology, fairy-tales, westerns, film-noir, etc... Superhero movies are just the new version of the kind of stories that people always wanted. And why are they popular now? Because modern technology makes them easier to make well. And technology only gets better with time, so...
When they're bad, though.... Yeesh. 'Man of Steel' was PAINFUL to watch, and 'Suicide Squad' was ALL of the cringe, and don't even get me started on BvS... The 'Amazing Spiderman' films were terribly weak, too. I don't watch many bad films, though... I never watched any of the Fantastic Four films, or the last 'Sin City', and I didn't watch BvS in the cinema, etc... No one ever said you HAVE to watch these films, right?
Will the superhero trend continue? Well, it will continue for at least a few more good years, I think. At LEAST until 2020, IMO. I think it might weaken by 2025, but who knows? These films have been going strong since around 2000, and they don't show any sign of slowing down. Even a stinker like 'Suicide Squad' made tons of money, and as long as these films make money, they will get made.
I do wish that Zack Snyder will never direct another superhero film again, though. Him getting fired will give the genre another couple of years to exist.