The bikes aren't the problem. Stock bikes are surprisingly quiet. As someone who likes riding (Suzuki Bandit 600, Yamaha XT660X) and is perfectly happy with stock pipes, I don't appreciate being lumped in with the idiots, and I would absolutely fight against a ban.
Absolutely, the people are the problem. Those are clearly not Harley bikes though.
No on is proposing a ban on 2 wheeled vehicles, or at least they shouldn't. But I'm all in favor of banning ANY vehicle that can't pass a very strict quiet test.