The big problem here is that you've lumped absolutely everything "unofficial" into a single category, and I find that that's not how most DMs work.
Most DMs have a hierarchy of acceptability. These ideas became really blatant (and tended to get ossified) during 3e, meaning a lot of games are still heavily defined by perspectives held when 3e was the "only" game in town.
Inherently Acceptable: Content the DM herself made for this game
This one's sort of a no-brainer. If the DM made it for use, it's inherently acceptable; indeed, it kinda comes before any real thinking about acceptability, because such things are often something the game in question is predicated upon.
Presumed Acceptable: Initial core books, explicitly-approved homebrew
Again, sort of a no-brainer, this is the "ground floor." If the DM starts off by saying, "I approve <3PP book> for this game," well, they're signalling to you that it's been vetted for acceptability. It's still possible that there could be an unforeseen interaction or problem, but it would be just that, unforeseen, because the content was expected to be acceptable.
Probably Acceptable: Official supplements of good reputation, well-known and high-quality third-party content
This is where we start getting into some ambiguity. Many DMs, particularly for 3e/PF games, know about a lot of prominent third-party products, and some of them are less "you definitely can use this" and more "I want to be asked but will probably say okay."
Potentially Acceptable: Obscure but still high-quality 3PP, official supplements of ambiguous reputation
Here, the fact that something is official is shown to not strictly guarantee that it's acceptable. For 5e, much of Unearthed Arcana fits here, and some DMs feel this way about certain specific books. For 3.X, Dragon Mag stuff tends to appear here. Very little from 4e appears here or lower.
Unlikely Acceptable: Medium-quality 3PP, official supplements of poor reputation, homebrew acquired from the internet
Lotta content here, simply because that last one is a HUGE source.
Never Acceptable: Explicitly-banned things, D&D Wiki content
I've literally never seen a DM who was willing to permit D&D Wiki content, so it gets special mention. Even DMs who are radically permissive, we're talking "let's mix all of 3.5e AND PF, all Dragon Mag content is allowed, AND you can gestalt multi-track PrCs together" level of permissiveness, won't let people use D&D Wiki content. It has that bad of a reputation.
So you get this hierarchy of options, and yes, officialness tends to make something more acceptable. But it's not axiomatically more acceptable, as the tarnished reputation of Dragon Magazine content shows, or the rather dramatic popularity of the Spheres of Power/Might 3PP line shows for Pathfinder. (Ironically, SoP+SoM is actually closer to 4e than it is to classic PF, just with things that are a hair more loosey-goosey narrative, and which function a little bit like 4e's Power Points system.)