I said Blade started the current superhero craze, not that it was the most popular. It was successful with using a superhero character, leading the other studios to take more chances with the genre.
If you want to argue most popular superhero movie, that would be the Avengers, but that didn't start anything.
Blade is not a superhero. He's a comic book character. If appearing in a comicbook makes you a super hero then Scrooge McDuck is also a superhero.