I think the problem is that the author doesn’t want to demonize any of those actual ideologies that oppose TESCREALism either explicitly or incidentally because they’re more popular and powerful and because rather than being foundationally opposed to “Progress” as he defines it they have their own specific principles that are harder to dismiss.

This is a good point. I'll go even further and say a lot of the component ideologies of anti-TESCREALISM are stuff that this author might (at least nominally claim to) be in favor of so they can't name the specific ideologies.