It's harder to be a dissident than ever because everything has been politically weaponized and the public discourse is absolutely saturated with bad faith argument.
"But most people in field X believe that Y is crazy talk, and there's literature going back 127 years explaining why they have come to that conclusion"
"Sure, but they won't be nice to me if I try to work in field X"
"Right, but that's because they believe, and can explain why, they think you're crazy"
"They are destroying my life".
I've attended classes as a listener where the professor was lecturing about how attempts to go to space are just modern equivalents of racist White Colonialism. I don't think there's a limit to how stupid people in supposedly high positions in society can be.
It's the behavior of the person espousing the belief.
I can imagine an entirely rational and quite deep argument regarding whether or not attempts to go to space are just modern equivalents of White Colonialism. And I might not agree with one or all sides of such an argument, but they are not prima facie ridiculous.
What makes them ridiculous is a failure to engage with counter-points, a failure to grapple with reasonably established facts that conflict with the stated position, and a failure to engage in falsification (i.e. "well, if X and Y, then clearly my position would be wrong").
Someone who can do those things on behalf of their stated position deserves respect, but someone who cannot deserves much less.
Discussion is a commons. It relies on trust and symmetric cooperation. When those things are betrayed, the commons breaks down.