I don't have a problem (within reason) with a player letting off steam because he kicked the ball out on the full - or kicked a behind instead of a goal in a tight match.
I do have a problem when he berates the umpire because he kicked the ball out on the full or kicked that behind.
As for providing feedback to umpires, that's the role of the umpiring coaches and not the public to bundle up a tirade of abuse and loosely call that "feedback"! 50m penalties might seem harsh for verbal abuse by players but the problem is there's a drop-off rate of something like 25% minimum of first year umpires. Something has to be done to stop this trend otherwise there just won't be umpires in 10 years time. You don't get this in cricket or tennis - why should you cop it in footy?
make it a full-time job.
you pay peanuts, you get monkeys...