There's also the issue of Nutomic being a core Lemmy dev. While something can be said about detaching the art from the artist, having alleged* bigots be involved in the long-term planning of a project raises question of whether they'll let those opinions influence the direction of the project. For example, if somebody created a pull request to add pronouns to user profiles and it was rejected, would it be for a valid technical reason or bigotry with plausible deniability.

* I say this because I'm not looking to get instance banned at this time.

but wouldn’t it make more sense to just migrate to an instance without an openly transphobic admin

That's really just too passive for me at least, much prefer to occupy a space and make the transphobes leave.

Unfortunately, there's no friction-free way to migrate. On Mastodon, for example, you can migrate between instances by exchanging codes between your old and new accounts and, in time, your posts, comments, memberships, followers, etc will move across automatically. On Lemmy, however, that's not an option and you start from fresh with on the new instance.