Leafs fans love a scapegoat.
Mitch hasn't been great by any means but he has plenty of company that is getting a pass for some reason.
I think people are fed up with the core as a whole.
Marner is getting pushed forward because of a few factors. He has the worst playstyle of the core for the playoffs, he's not performing, he has a terrible track record in the playoffs, can't handle the media, and is next up for an extension. Everything is working against him right now and he's rightly getting torn to pieces.
If I compare them, Nylander had a decent run last season (looked acceptable last night too), Matthews just dominated game 2, and Tavares works harder than Marner even though he's complete rubbish and past his prime.
Keefe, Marner, and Tavares need to be gone. If Marner is getting more heat then that's fine because he's deserving of it.