I feel like refereeing has become more game management than rule enforcement nowadays.
You have your automatics. Other than that, a lot of the calls seem to be because the team has worked up to it or is due because the other team has got plenty, or they're make up calls for past events, or calls made to try to control emotions. And plenty of non-calls seem to be about "letting the players play" towards the end of the game, because they want to crack down on known offenders, or things like that.
Especially the idea of "letting the players play" irks me, as it way too often favors the team on their heels, or the team that is not as disciplined, or plain uglier. Way too often, you see the refs start to let everything go and a non-call ends up being directly responsible for a game-winning event.
This isn't about my team, btw. I'm of the opinion that if you really want to deserve to win, you get yourself enough margin that a mistake from the refs don't change anything. I just want better quality, and I think this is a problem area for the game today.