To be fair...
There are alternatives to Lemmy. Kbin, I'd argue, is superior in most respects. (Kbin is still obviously young and rough around the edges at times, though.)
I don't like the Lemmy maintainers, and that was a big jump propelling me onto Kbin. It just made me feel squicky knowing that I was tacitly endorsing their software by using it when there was an alternative available that did exactly the same things. I also don't like using communities on Lemmy.ml because the admins there have a history of removing stuff that doesn't suit their political views.
I don't think these two situations are equivalent, mind, but I do think there is more weight behind "avoid using Lemmy" than "avoid using Calckey/Firefish".