the reason that a black panther movie would be so great is sheerly because he's an obscure character. when you have a hero with a completely set, popular plot distributed en masse that everyone recognizes already you can't do so much of the fun stuff that you're able to do with obscure characters---that's why guardians of the galaxy was so goofy but still had a great serious plot structure despite their obscenely high humor content
dunno man, i couldn't ever see a captain america movie happening with the same things that came out of ant man