That’s a nice maxim and all but in actual reality, the vast majority of people on the vast majority of topics have to use heuristics to build (and disconfirm) their beliefs. The people who are actually close enough to a topic to even be able to judge an idea “on the merits” are few and far between. If you want people to have an accurate model of reality, you have to care about maintaining heuristics that at least somewhat track with the consensus (or the lack thereof) of the underlying group of people who actually have a chance of knowing things from first principles and direct experience.

Deliberately sampling an “unbiased” subset of an actually biased underlying population is not just allowing the heuristic to stray from reality, it’s deliberately destroying that heuristic and deliberately misleading people. In imaginary “everyone can/should judge on own merits”-land, that’s perfectly fine. In reality, where almost no one can actually judge almost anything of substance on its merits, you are actively sabotaging truth-seeking.

The way that fringe scientist gets to declare s/he is right is by convincing their peers of it, not by convincing the public in a format that violates the heuristics the public has to rely on. Of course everyone should always be open to this possibility, most of all their peers (and to your point they often aren’t!)