Yes, the criticisms are valid, up to a point.
Rostering refs was a nightmare. We had too many games, and not enough referees available.
We have a lot of referees at the miniball level, but lose a lot from the next level (Saturday Morning Juniors)and up.
We had ABA games programmed for the weekend, so the "panel" refs priorities were with them. That cuts out around 20 of the better refs for the junior reserves championships. A number of refs were unavailable because they were playing. We had a number of refs refuse point blank, to ref anywhere else but where they "always" ref;they refused to go to another stadium to fill gaps. We also had to deal with refs who had a "percieved" conflict of interest, e.g. a brother or sister playing in a team on a game for which they were rostered, meaning we ended up with a less desirable combination of referees on a particular game. We had a number of refs who indicated to us they were available, then backed out at the last minute, as usual (not always the same ones). This meant that just to fill vacant spots, we had to put people on games that some of them were not ready for. What was very pleasing from a development point of view, is that so many actually showed that they were capable of "stretching" to the standard of game that they were on. Of course, some didn't. That's life.
What some you forget when you criticise referees, is that ALL of them are developing skills and learning, just as ALL of the players and coaches are. Just because one individual has a different opinion does not mean that the referee is necessarily wrong (or right!), or bad or good. Also, how you treat someone, be careful. You just might get the treatment you give, no matter whether you are a referee, player, coach, or spectator. Treat everyone with respect, and you will get that respect back.