I feel like 75% of Mastodon are people talking about Linux. If you don’t care about Linux you feel alienated. I enjoy Mastodon and Lemmy, but the lack of more diverse subjects gets to me if I browse for too long.
Update: I took your advice and purchased a laptop for Linux, and now I care about it! Problem solved.
The nice thing about federation is that if you don’t want normies you can just defed from instances that allow them, or anything with open sign up.