They want Greenwood to be cleared because he was a sensational talent, and could've been our striker/right winger for the next decade. He was already very good for us, and would only get better.
Antony has cost us a fortune and disappoint in a lot of ways. Even though he should be given more time, it's evident what kind of player he will never become, even if he improves in other ways. People think he has been a massive failure (he really hasn't, it's just the transfer fee, which he can't help). These fans would much rather want him replaced than him to be freed of these charges, so they hope he will be found guilty, which means they also hope that his ex-girlfriend was beaten up. It's disgusting.