NBA refs get a lot more hate than they deserve from entitled/annoying fans. A lot of people let their own biases affect their judgments, when the refs are actually being reasonable. Fans will screech about how terrible a call or non-call is, but in those cases the refs are right, not the fans (like the infamous one earlier in the playoffs where on the replay the refs weren't allowed to judge the player out of bounds).
The fact is, NBA refs are very good, overall. Yes, they have bad games, they make bad calls, but that is inevitable. It is literally impossible to be 100% accurate. And some of the supposed problems with the refs are actually problems with the rule system that the refs are following (flopping, for example; shooting fowls, etc.).
Honestly, anyone crying about the refs fixing the games is just a whining loser. It is easy to cherry pick missed calls or bad calls to make it look like their is a conspiracy, while ignoring the 20-30 good calls the same ref makes that game.
That said, the refs aren't perfect, and there is room for improvement. I think the best thing for the NBA to do is simply encourage the refs to be more conservative with their whistle. When in doubt, don't blow the whistle. The game would be better with more non-calls. Missing a foul is better than frivolous calls.