When I first made an account I did it on Lemmy.ml because that’s what I had heard some people talking about and didn’t know it was one several Lemmy instances. I wasn’t aware that ml stood for marxist-leninist, and switched over to the the other I knew about .world.
I can see the average joe joining the wrong place and seeing an echo chamber or an essential empty isolated instance then forming their opinions on the fediverse around that.