@ALostInquirer@lemm.ee I think part of it is the "branding" of Mastodon - if everyone someone follows uses a Mastodon server, they might just think of "Mastodon" as the social network they want to join, and never really consider that other people on the network might be using something like Firefish or Pixelfed or microblog.pub. After all, most Mastodon servers' web UIs look pretty much the same and the default Mastodon name and graphics are often pretty prominent.

I don't think this is usually an issue, but there are some Mastodon instances out there whose names are `mastodon.[something] and I think that can mislead people into thinking that's the one they "should" join just because it seems "official".