Firstly, that's the leafs. Secondly, really, the ACC hasn't been THAT loud all season. It only gets loud when the leafs are playing good and playing in meaningful games. Like its not loud from the face-off, they're not continuous chants etc. In all cities you get rambunctious sports fans, its the frequency and general ethic that matters. Toronto really isn't that spectacular in that regard.
And we're talking about noise here, not 'support'. I agree that TO fans love their sports and teams and MMA.