Have you considered that some of the crazy sounding people might be intentionally associating crazy ideas with a counter establishment movement? So that the movement is discredited by association.

The establishment has a clear incentive to do this, I would be kind of surprised if they were so pure as to abstain from it. Sure, some gullible people actually go along with the crazy, but I think those are likely a small minority of the counter establishment movements by people count.

The transitive negative social vibes of the crazy ideas makes non-crazy people reluctant to discuss such counter establishment movements in public. E.g. perfectly rational reasons to be cautious about a new vaccine platform are drowned out by and associated with crazy ideas about microchips and 5G, like you say.