It's possible, but if, say, pro-pinapple speech and reesearch is effectively and heavily suppressed, then even if the lone nutters who are pro-pinapple (and you'd have to be a bit of a nutter to be pro-pinapple in an anti-pinapple world, both due to lack of exposure to anti-pinapple resources and for social reasons) speak up they are probably not going to make a good case, not having had the opportunity to explore the idea with a large number of different people helping them figure out the arguments and doing the experiments.

That retort does not work when the suggested policies work every single time as promised when they have been implemented and their primary reason for failure is that they have been made illegal and brought to court.

Also, the refutals that supposedly make them unpopular seemingly have no impact in reality. That kind of suggests that either the models used for refutal are grossly incomplete or big errors have been made due to political reasoning.

If you believe you have the best ideas with the best evidence backing them and find you can’t reach people with the plethora of modern communications tools, I’d spend at least as much time examining possible faulty links in your beliefs as I would the possible failures in communications.