35 years ago we didn’t have the cultural precedent/zeitgeist of getting cancelled for some stupid shit you wrote on a message board in 1991 so we were less guarded with our opinions.
I might suggest that "projection" is a primary motivator, although I work to avoid projecting on my own time.
(Edit: To disambiguate without vagueness: When some fucking party or other is talking about "cancel culture," they usually seem, to me, to be projecting about their own fucking party's fucking ugly policies and tactics.
And in a sane and pure world, I'd like to wish that they'd be recognized as being fucking scumbags for behaving in this way.
But it is my observation that we do not always live in a sane and pure world.)