And can it be improved?

To much judgement involved. Different rules (unspoken) for different locations on the court. They allow a lot more contact when your back is turned than when you are facing up, more contact is allowed in the lane, etc. Defenders sometimes have a right to their space, most of the time they don't, etc.

Any game that is less than 5 points could have easily gone the other way with different timely calls. Game could easily be fixed.

I enjoy watching it when I am not vested in a team; however, it is the most frustrating sport to play or be invested in due to the power officials have. Non-calls, bad calls, either way calls, etc.

I play in a yearly league and honestly (we only have two refs); its more fun when I play pickup games/call your own foul. Officials have a very hard job. "Adults" calling their own fouls are more accurate (but is the reason for all the arguments and fights in pickup games).

If they called all the contact the same; there would either be 150 point or 20 point games in high school and they would last 4 hours.

I love the game but it is very flawed.

While NBA officiating certainly isn't perfect whatsoever, I think there's a couple direct reasons which lead to it being widely criticized more than the other major sports.

I think player and fan reactions are some of the biggest reasons it's so widely criticized for one. The NBA is the most fan-engaged league out there in terms of actually seeing/feeling emotions and being on top of the players in the arena. You see every emotion/thought these guys have and seeing a players reaction to certain calls just enhances the perception that there are so many "bad calls". Those reactions directly result in the same type of fan reactions which gives the common fan or somebody who might not know a ton about basketball the perception that there's a ton of bad calls being made.

While officials in football certainly don't have the same impact on the game, it's officiating does not get the same scrutiny because you just don't get the same type of reaction from the players/fans due to the uniforms and being so far away from the field, etc. There's missed holding/pass interference calls every single game in football that directly impact the outcome of games. You might see the coach go yell at the ref but that's it and it's on to the next play. Nothing like the animation coming from the players/fans in the NBA.

Pair that with the fact that you have 10 of the best athletes in the world at 6'6+ running/jumping at full speed on a court that's 94' x 50', You have an incredibly hard sport to officiate.

Very comparable to the line of scrimmage in football where technically a hold could be called on every play. As fast as these guys have become it's so hard to see everything in person in full speed. That's why you see so many delayed calls, they wait for the outcome and then blow it saying clearly there was a foul. We have every angle sitting at home, the officials do not. I do think there are some crews that try to be too much a part of the game but not always.