Sure Marvel has made a few duds. But they've made Iron Man 1, Avengers 1, Guardians, Winter Soldier, and Civil War too. Indisputably I think many would agree that's about half of the top ten best superhero movies to date. It just is.

DC hasn't made as many movies, much less as many good ones. It's their own fault that they get compared to Marvel because a) the output isn't there and is way behind and b) what little output there's been has been mediocre at best.