I think this anti-theism conflation comes because of the commonly used philosopy of religion definition being "the belief gods do not exist" and because the colloquial definition has shoehorned anything that "lacks a belief" as an atheist, they've also had to rebrand anti-theism.
The funny thing is, this use of anti-theism isn't even how the often celebrated Christopher Hitchens used it.
Quoted below, this isn't just a belief gods do not exist, he maintained the belief that religion is harmful, and thus is an anti-theist...
Now, folks can identify how they like, but it does bother me when folks say "atheism is only" or tell me I am an "anti-theist" due to some weird redefining of the word.
I also prefer concise and precise language.
I don't find broad terminology that useful.
You're free to conflate all non-theists with atheists
And you can apply that to other things too... Consider though, do you regard
All non-brits, American?
All non-dogs, cats?
All non-humans, pigs?
All non-fords, Ferrari's?
All non-cars, boats?
I've said language is descriptive and people are free to identify how they like a number of times, but when discussing definitions I speak of the normative (answers-in-reason.com/philosophy/epi…) or most logical.
This can be met with some hostility, with people often telling me I am the one being illogical or that I don't understand what normative means, with some rejecting how normative is used in philosophy with a preference to a colloquial use.