...the title character doesn't appear in the first 30 minutes of the movie.

Corollary: Showing the title character that early doesn't always guarantee success, but at least folks can't complain they didn't get what they paid for.

The character doesn't have to be in full regalia, and the character doesn't have to be in full-on-hero-mode, but if the director willingly choses to not actually deliver the the TITLE of the movie (especially a comic book based film) that director has severely crippled his chances at winning audience or critical respect for the work.

Whatever Ang Lee was trying to accomplish with his version of the Hulk was diminished/negated by the fact that there was nothing remotely "Hulk" about his film for an incredibly long time.

IIRC (it's been a while since I saw BB) in that movie, much like the rest of Nolan's work, the film has an immediate temporal transistion so that the viewer knows the arc that the title character is travelling.

As I wrote, you don't need to see the full regalia, but if the "hero" is there, audiences will have a better love of the movie. Donner's Superman doesn't appear in the tights for a long while, yet it is clear early enough that the movie is delivering the title character.