I have been contemplating this point. One of the things that sets off red flags for people outside a group is when people in the group appear to have cut'n'pasted the leader's opinions into their heads. And that's definitely something that happens around LW.

The failure mode might be that it's not obvious that an autodidact who spent a decade absorbing relevant academic literature will have a very different expressive range than another autodidact who spent a couple months reading the writings of the first autodidact. It's not hard to get into the social slot of a clever outsider because the threshold for cleverness for outsiders isn't very high.

The business of getting a real PhD is pretty good at making it clear to most people that becoming an expert takes dedication and work. Internet forums have no formal accreditation, so there's no easy way to distinguish between "could probably write a passable freshman term paper" knowledgeable and "could take some months off and write a solid PhD thesis" knowledgeable, and it's too easy for people in the first category to be unaware how far they are from the second category.