I don't know much about Kick-Ass, but Deadpool positioned itself as a parody of superhero movies, and that changed the expectations from both financiers and movie audiences. It didn't promise spectacle and action (though it contained it), it promised self-awareness and zany jokes.
A low-budget (comparative, $50 million is low budget for today's comic book movies, but astronomical for most everything else) Batgirl or Nightwing or Martian Manhunter movie would be in a different situation. They won't have the brand recognition of say Batman or Joker to bully through the saturation of the media landscape, and the lower scale of production budget won't justify the marketing needed.
Now, Matt Reeves's Batman might change that. A well-received noir Bruce Wayne-focused Batman movie might change the expectations on what a good superhero movie should look like.