he's almost right, except he doesn't understand correlation, causation, or nuance, so in turn is just completely fucking wrong.
the problem of the move to comic shops as a dedicated storefront is that it drove up prices, which in turn, made it more of a niche hobby. The idea of a "serious comic collector" was absurd in the 1960s, a tertiary market after "those kids who will buy comics for about two years before they age out of them, so we can recycle ideas every 28 months and people won't really notice."
by refocusing from the primary market to a tertiary one, they were able to focus, boost interest in that group and convert them into higher spenders. This was both profitable and good for the art form, since it allowed growth of more mature titles. There would be no Watchmen or Dark Knight Returns without the comic shop move.
But since this raised the bar to entry, it reduced the number of new entries into the hobby every year, and became increasingly insular.
While it does not necessarily follow that a community that has been insular for 40 years will also be backwards in other senses, there is also no internal incentives to change to match the outside world.
Broadly speaking in my experience, comics fans are among the most liberal or most conservative people in the country with very little in the middle, possibly in no small part because of both the power fantasy involved in superheroics attracting both savior-complex Great-Power-Great-Responsibility types as well as Good-and-Evil-are-black-and-white-and-violence-is-the-answer types who have been arguing amongst themselves for literally my entire lifespan.
Which then leads to problems when the broader society is imprinted on that insular, arguing collective. The liberals will see the tokenism for what it is, and the conservatives just resent the presence, but we end up with a whole community that, to the outside, appears to be inexplicably racist, sexist and backwards.