You have some good hypothesis. One other: a lot of left wing activist types (who are disproportionately noisy) have very strong ideological purity preferences, so a person with mainly left wing views but some right wing views can be condemned for the latter, and likewise a movement with mainly left wing people but a few right wing people can be condemned. Any sufficiently public person or movement, unless they are very homogeneous or very PR-conscious, will eventually reveal they have some diversity of views and hence be subject to potential censure.
You have some good hypothesis. One other: a lot of left wing activist types (who are disproportionately noisy) have very strong ideological purity preferences, so a person with mainly left wing views but some right wing views can be condemned for the latter, and likewise a movement with mainly left wing people but a few right wing people can be condemned. Any sufficiently public person or movement, unless they are very homogeneous or very PR-conscious, will eventually reveal they have some diversity of views and hence be subject to potential censure.