They used to use the record-based system that the other leagues used. But quite awhile ago, some moron(can't remember who)officially affiliated with a team as an executive actually came out and said he had advised the players that losing the rest of their games wouldn't be a bad idea. Instead of slapping the sh!t out of this fool; they decided on this method so that teams wouldn't "tank" the rest of the season.
There was no 'this fool'; everyone was doing it. The tipping point was a Rockets game leading up to getting Ralph Sampson, if I recall, where both teams looked like the Washington Generals absent the Globetrotters; just comedic play at the end of the season.
This 'fool' was at least being honest about what teams were doing, for years.
The fundamental problem with the NBA is far, far too much emphasis on the individual and too little emphasis on the team. If LaBron James and Kobe and Shaq and Wade and Arenas et al are fouling out of games commensurate with the fouls they commit, suddenly having the best 8-10 players is more important than having THE ONE with his helpers.
In the NFL, getting the #1 pick is nowhere near as critical. There are no Tom Brady's in basketball to be picked up in the latter rounds.
So, I say call the damn game. Make teams protect the stars by having depth. David Stern and company decided in the Bird/Magic era that the league would do best promoting individuals over team. It's the antithesis of why college ball is so great; team matters.