If you're going to tar them as an "arm of the culture wars" you're going to have to do a little better than this.
Maybe they make fun of Republicans more than Democrats but that's only because it's like shooting fish in a barrel with the GOP. There's more to mock.
(INB4 buttery males)
I'm not crazy about them fact-checking satire, but it's incredibly obvious why they have to--because people treat them as a one-stop-shop for finding out whether an article is real or not. For The Onion that might be easy to answer, but there are also a lot of terrible, unfunny wannabe satirical sites, and people do get confused.
True, that ("fact-checking" satire) is not an act of culture war. It is a behavior that makes them very questionable candidate as an arbiter of truth, which Facebook seems to have anointed them to be.
> but it's incredibly obvious why they have to-
No it isn't. On the contrary, them confusing "checking" satire and checking real facts blurs the lines between fictional expression - which can't be rated as true or false as it is not a factual statement - and factual claims which can be evaluated as true or false.
> people treat them as a one-stop-shop for finding out whether an article is real or not
That's a bad thing, both from the point of view of robustness - that means that people surrender their agency and critical thinking to some random site on the internet - and from the point of view of choice of that single point of failure - by choosing the site that can't even go as far as distinguishing between factual statement and fictional expression and routinely confuses the two.
If they just said "The Onion is a satire site, the Bablon Bee is a satire site, that's it, move on" - it'd be fine. But the way they do it - to actually evaluate it as a factual statement and assign rating "false" to it - is mixing two concepts, and it's a bad thing. "Fact checkers" regularly commit the same thing by "fact checking" opinions they oppose as "false" - and that is very much a part of the culture war, an attempt to present one opinion as "objective fact" and the opposing one as "objective falsity". Snopes did not do it in this particular case, true - but they did it in other cases, as well as other "fact checker" outlets. That predictably hurt the reputation of the whole business.