Football is a contact sport already – always has been, but there are lines that you don’t cross. I.e. you can muscle someone off the ball but you can’t just plough through them, pull them back or use your elbows.
Cynically elbowing someone isn’t an agressive challenge, it’s violent conduct and should be punished as such.
Sadly, over-aggressive players and cynical diving have made it impossible for refs to judge this.
Carling Cup Final as a case in point – the players would not commit to a challenge in and around the penalty area as there was a very good chance that a clean hard tackle would be seen as a foul.
It’s rubbish. Make diving a professional foul and make it retrospectively appliable via video replay with a default win for the opposition (so there is no incentive).
Then refs will have more comfort is using their judgement to decide on agressive challenges and violent conduct (e.g. elbowing.)
Some players and a lot of supporters cant understand the difference between being hard and fair, and being agressive. The former is what its all about, the latter isn’t.