Stand-Alone vs. Combined Universe
Let's be completely honest here. Daredevil, as fantastic as the character is, wouldn't have much to do on the Avengers team. He's a street level fighter who's massively sensitive to sound. Had he been in the end scene of
The Avengers fighting along side the team, he would have spent the majority of the time on his knees with his hands to his ears in pain at the explosions, screaming, and gunfire. Cosmic war is not his element. And that's perfectly fine. Not every character needs to be like that. When it comes to Matt Murdock, he's a prime example of a hero whose alias is less important than the man himself. Batman overshadows Bruce Wayne. The Hulk overshadows Banner. Clark Kent is just a ruse for the true icon of Superman. But Matt Murdock is Murdock before Daredevil. Writers like Stan Lee, Frank Miller, Ed Brubaker, Kevin Smith, Brian Bendis, and Mark Waid have explored that extensively. He's a renegade, extremely adept martial artist and gymnast, but that's all second fiddle to his psychology as the lawyer seeking order in the chaos of both a professional and private life. Which leads us to the fact that unlike the majority of superheroes, Matt Murdock
actually has a full-time job. Batman is rich. Iron Man is rich. Bruce Banner is a scientist always on the run, Reed Richards is a scientist always making...stuff. But none of them are actually employed. Sure, Peter Parker takes pictures for The Daily Bugle and Clark Kent is a reporter, but Matt Murdock is one of the few heroes to actually have to worry about paying the bills with a steady, demanding job (the only other one I can think of off the top of my head is Barry Allen's Flash, who is a forensic scientist). Which means that his work is imperative to his life and story. A Daredevil movie should be a bit of a legal drama, as well. It would definitely put a new spin on the superhero genre. But that means we spend adequate time not exploring the realms of roof-jumping herodom. And I, personally, don't find that possible with Daredevil being committed into the
current Marvel Cinematic Universe. Let him get his own breathing room without being swamped with lawsuits because of the Hulk's destruction in Harlem.