In UI/UX design they're the opposite of power users, technologically illiterate, bandwagoners, PC culture, the 90% of a social media site's users, average joes, your grandma on the internet. They're used to the conventions of other sites and have little appetite for complexity in their search for content.

None of this is meant with any bad connotations. They're a user class with a distinct set of needs. Beehaw blocks them due to the registration hassle. Kbin is maybe 75% of the way there. Much of the fediverse is decidedly anti-normie. Marxist-Leninists and edgy teenagers abound.

Note that the reason normies have a bad connotation is because their influx leads to a certain homogeneity and a stripping of established cultures. The term is used as a slur to counteract this effect. Those with anti-popular tastes will centralize elsewhere usually.