Apart from the poor standard of referees who do not seem to have a grasp of the rules of the game, I don't think matters are helped by this obsession of 'letting the game flow' which means infringements are sometimes punished and sometimes not. In these circumstances professional sportsmen and their coaches are invited to take liberties.
Some years ago in a match v Leeds at Wilderspool there was a newish referee called Cummings in charge and a promising young forward called Morley playing for Leeds. Cummings, in the first half, quite rightly IMO, penalised both sides for every infringement and the crowd were whinging about the stop start nature of the game. However, in the second half, both teams got the message, played to the rules and the game flowed much better. Also In the second half Mr Morley walked for persistent head high tackles (Does that ring a bell) and I thought Mr Cummings had done a first class job.
Morley got sending off sufficient which was ridiculous and I can only think Cummings got a talking to about 'letting the game flow' because I have never saw him referee a game like that again.
What is the point of having a rule book if,
1. The referees don't know the rules.
2. Selectively apply them or
3. Ignore them altogether
When a ref's decision can have such a crucial effect on the outcome of a game, it seems farcical to me.