For a non-technical user, or even a neophyte, the mere act of finding a Usenet news server is difficult.
This might be a good thing. All that is required is a little research and gumption. Filtering out those without that means a higher grade of users.
I disagree. If they cannot follow basic instructions to get into a system, and we are talking very low bar here, they probably are not going to be able to successfully operate any kind of discussion forum.