This is all to say that equating being against unions is about as far away from sexual predators and racists as communists are. You might be fringe, but it'll never get you cancelled. I guess unless you're trying to cancel a union or run for union leadership positions.
Don't forget that conservatives invented cancel culture. We still have Christmas and Harry Potter and witchcraft. Your anti union prejudices are fine.
https://www.washingtonpost.com/opinions/2021/02/19/nobody-lo...
I'm talking about Brendan Eich, who got forced out of mozilla because of his donation to support proposition 8[1]. In the end the proposition received 52% yes, 48% no, so it wasn't exactly a fringe position.
[1] https://en.wikipedia.org/wiki/2008_California_Proposition_8
https://www.axios.com/ceo-political-activism-03b148a0-d921-4...
How does this relate to the initial discussion? The end result is the same: your commenting behavior right now may jeopardize your career 10 years from now, therefore people are taking steps to mitigate that risk.
because anti-union rhetoric tends to get downvoted to hell and is received negatively for some (see for instance, the first sentence of your comment). With how cancel culture is going these days there's also the concern that 10 years from now someone will dig up your anti-union post and use that against you.