Marvel Studio's President Kevin Feige has shared that the secret behind their superheroes success is diversity.That is why they still give full attention to the solo movies-not just the team.

He explains the dilemma of Captain America in the new movie "Captain America: The Winter Soldier." Speaking to HitFix:

"I don't mind if it feels old-fashioned or out-of-place. He is out-of-place and he is kind of old-fashioned in the modern era. Part of his conflict with Fury and some of the other members of S.H.I.E.L.D. is the fact that he's from a different place, he has a different set of values. At least he thinks he does, initially.

We're careful not to make him a goofball fish-out-of-water. We don't spend a lot of time with him trying to understand what an iPhone is. If you took a 27-year-old and introduced them to something they'd never seen before, they'd probably figure it out. They wouldn't be completely flummoxed."

The contrast between the heroes-Captain America's Old School approach versus Iron Man's modern disposition for example, was part of the charm that brought "Avengers" to a staggering $1.5 billion reception and Feige understands that:  

"We make a lot of superhero movies here at Marvel Studios. and I believe the key is to make them all different, and to make them all unique and to make them all stand apart while connecting together. That's what the comics do." 

This is why they do not neglect the other trilogies and the solo features in the future. They need to remind "the moviegoing audiences that these characters have separate adventures, but then team up as The Avengers every once in a while. Just like comics. So far, with 'Iron Man 3,' it's worked. People didn't throw tomatoes at the screen, going, 'Where's Nick Fury?! How come Thor doesn't help him take down Guy Pearce?!' People are accepting that there's a time when they should be together, and there's a time when they're not. The more moviegoers that see these movies, the more 'Inside Baseball' you can be. The continuity of the films is becoming known and accepted."

In the comics though, the Avengers are more organized. They had a designated leader and their own headquarters. For now though, Feige maintains this status quo.