We need some fraction of respected scientists -- even a small fraction -- who are crazy enough to engage even with potentially crackpot theories, if only to debunk them. But when they do that, don't they risk being considered crackpots themselves? This is some version of "Tolerate tolerance." If you refuse to trust anybody who even considers seriously a crackpot theory, then you lose the basis on which you reject that crackpot theory.

(Original post.)

More generally, one can't optimize a process of getting some kind of answers by also using such answers in particular cases where they already happen to be available. Adding this one rule collapses the whole process, as it begins to reuse arbitrary and trivial data, instead of actually doing any work. In particular, this is the reason for the groupthink failure mode. (And Loeb's theorem!)

Thus, it's more precise to say that the problem results from taking on faith that intolerance by others is justified, rather than protesting against excessive tolerance shown by others. When you believe others are wrong in showing excessive tolerance, you make that judgment by yourself. You should be wise to not make that judgment unless you know enough. On the other hand, if you observe that others in your group (or in mainstream) don't tolerate a certain class of pursuits, concluding that this class of pursuits doesn't deserve tolerance just from that is a failure mode, since this social dynamic could red-flag anything, no matter its merit. All it takes is ability to reliably induce that one inferential step, when a person newly introduced to a question looks at existing consensus and leaps to conclusion just from that, without actually considering the question.