I don't think it's wrong for other Fediverse projects, besides Mastodon, to exist.
Especially since so many of them predate Mastodon.
#Misskey, which is what #Calckey is based off, predates Mastodon by two years!
Friendica started in 2010.
GNU Social is even older.
And people forget that Mastodon itself is a fork!
It's wild to me that so many folks believe Mastodon = Fediverse.