Think about why he compares gypsies to wolves, and talks about "self-preservation".
You might want to be pedantic and try to say he's not comparing them to wolves. He is the one who put those two sentences next to each other. You can choose to ignore the thing that feels obvious to others.
I know a lot of people are decently close to DHH in their feelings on this issue. I think that being publicly loud about these opinions that most people keep to themselves simply leads to wondering what his _actual_ deep opinions are. Think about what you say in private compared to what you say in public, and consider that he is writing in public.
A sentiment being common or not is a bit besides the point about whether it's authoritarian or fascistic or whatever.
If you remove the context and the implication from his post, you can make the argument that it's "just" a post saying "enforce immigration laws".
The problem is that the context and the implications are part of his post. He is communicating who he is and what he believes, and for you it's mostly a question of whether you're going to listen to it.
This whole line of discussion is had about DHH in particular decently often, and I find it kinda funny because even beyond all of this I've always heard that he's just kind of a disagreeable person anyways. But I suppose this industry pulls in a certain kind of annoying person.