I think what's missed is that most of the extreme, even if common, cases of people demanding heretics be punished, are really just trolling. Trolls are continually pushing the boundaries, and institutions are afraid to stand up to them for fear or being labeled heretical (ironically) so we have this feedback of more and more ridiculous stuff that nobody actually believes becoming mainstream. By fighting it the way PG is, it (trolling) gets legitimized. Feeding the trolls doesn't work, we need to to better to collectively tune them out, picking a fight with them puts you in their territory and you've already lost.
The evidence doesn't support your view that SJWs are "just trolls". A lot of SJWs genuinely believe that cancelling people for espousing wrong view is a real force for good. And they have some superficially good reasons for that belief. Trolls will use any weapon they can, so it's less interesting to debate them (except, maybe, about the nature of sadism).
