I still don't understand how a multi billion dollar league won't train and pay refs adequately
I'm curious how you know either of those things. I used to audit a bank whose President was an NFL official (umpire to be precise, when they still stood behind the D line and got trucked sometimes). Not only did they go through annual training, they had to be in the city the day before the game for briefings and assignments.
What is it people expect? These aren't guys reffing games every day for 6 months like in baseball, basketball, or hockey. It's once a week for 4 months. Would calling them all "full time" make them magically better, as if they're going to punch a clock and spend 40 hours a week year round in training?