I thought more about the lost revenue piece and wanted to dive into it. Under your proposal, each team would have 32 games eliminated during the regular season (going from 82 to 50). Cumulatively, that would be 480 games lost (32 X 15). During the playoffs, a single-elimination tournament with all 32 teams would be 31 games total. As the NBA playoffs are currently structured, there are 15 7-game playoff series, which means that there could be as few as 60 games and as many as 105 games. For the purposes of this exercise, let's meet in the middle and say an average year has 82 total playoff games. That would mean, in this example, the NBA losing 51 playoff games per year.
So, in this exercise, the NBA is losing 531 total games per year. Doing some light Googling, ticket prices and revenue vary wildly, but let's just say for the average team that it's around $1 million in ticket revenue per game. And thus, in this exercise, the NBA's revenue would be diminished by $531 million per year.
If you can figure out how to recoup a half-billion dollars (ballpark) in lost revenue every year, I'm sure they'd love your idea!