I think 'last weeks ref' has a lot to do with this. There is massive inconsistency between different referees on what they find acceptable and not acceptable behaviour.
If all referees took the same line on dissent and OFFINABUS, within a small amount of time, the rates at which they occur would lessen. However the main problem with this, comes back to the fact that it is a personal opinion of each and every referee as to whether someone has overstepped the mark or not. What I find offensive, the next referee may not, for whatever reason.
Like a lot of things in life, they work in theory. However, how and if this could ever be implemented, I doubt it.
How many times have we been watching a game, mainly local parks etc, and heard a player say something towards the referee, that we say to ourselves ''He would have walked if he had spoken to me like that''? But yet the referee on that day doesn't even pull the player up on it.
I have no doubt that if there was some sort of trail, even in a local Sunday league (if any such league would be brave / daft enough, is a different matter), that if a player verbally abused a referee using offensive language he would be sent off. I'm sure that there would soon be a sharp decline in the number of such incidents. However, that scenario still leaves you with the problem we currently face of being told to decipher between what is frustration and what is dissent or OFFINABUS.
After that, I still have no answer. Just wasted three minutes typing.