> The "license" is a PhD (from a reputable institution)

Maybe I'm biased as someone who has attained a PhD, but a PhD or master's is definitively not a license. It's almost necessary to have an advanced degree to be taken seriously, but that's not for reasons of normativity, but rather basic competence and a signal of investment. Your degree will not be revoked for the same reasons a doctor's or lawyer's license may be revoked (Francesca Gino lost her tenure, but not her degree). And IMO, your alma mater matters only as a proxy for your academic network; few in the academic world care if you went to MIT per se, but for the connections you made there.

I don't think there's an argument that the scientific establishment rejects many high-value contributions from uncredentialed/undercredentialed individuals.

> publications in a select list of high profile journals

Yeah, this is a serious issue. Although I don't know what it has to do with the question of whether the body of scientists proper should deliberate to establish consensus and distribute resources and prestige. If anything, Elsevier et al. have demonstrated that it can't be worse than letting the free market insert itself so insidiously.