Why are the refs so protected? Well gee, I think if I was consistently bad at my job I'd like to be protected too.
Agreed with both Chris and Rondo987 - the rule is in place for a reason, and that is to stop too much whining from happening. But if the coach is complaining about something and has a valid point, it's stupid to fine them. Doc Rivers was fined for publicly agreeing with the NBA's stance - that the referee did something he shouldn't have.
Ultimately, the officiating is the league's #1 problem. Not public perception about prima donna players, not small market teams, and in my opinion not even labor negotiations. Fans are starting to become too aware of how bad NBA officiating is, and it is eroding the fan base.