Damn, it's a tough one. Not many options but anyway, these are my choices:
Most affected: Endorsements/Money::
Think about it, no shoe contracts, no banners along the sides endorsing their product. Just like the 1950's. And so with the rate that the world travels, the NBA wouldn't be able to survive without support.
2nd Place: Crap teams::
Like Martin said- equal comp, no one would out do the other. Everyone would be as good as the other team. If someone wasn't crap, who would win? They have to be.
Honourable Mention: Matchups::
Doesn't really affect the NBA that much in that an team could have no star players and they could still be a good team. Although when you take in the "fan factor," people come to NBA games to see good matchups and seroiusly, good matchups bring good crowds (it's a cycle!)Which brings me back to endorsments. Without them, how would people know that there would be a good matchup if it wasn't advertised on websites and in papers?
Think about it...
Macca