You also have to realize that the clothing market is just brutal and that it's hard to survive. That's why OP and everyone else on this forum owns at least one piece of Nikie or Addidas gear. Certain brands have a stranglehold on the market and these black companies just don't have the financial stability needed for long-term.
Secondly, people wear what they wear based upon their circle. They want to be accepted (think a breh already mentioned this). If nikkas really came up to the club wearing FUBU they would get Insta-clowned. I don't know the exact reason why but that's just the way it is.