But these can't all be nutjobs.
Yes, they are.
Os and 1s either work or they don't. There's no "oh, this 1 sounds like 0.7526 only".
Thing is, yes, there's lot of issues that can be introduced by USB equipment.
Stuttering due to the connection not being solid, *check* (possibly caused by the same source as certain USB cables not charging your devices properly).
Higher pitched whine when using USB-audio devices - well, especially round these parts that should get a big *check* because I'm sure pretty much everybody was experiencing it here and there, just when trying to connect whatever device to run the software editor (or, even worse, using it as an audio interface). Most commonly a ground loop issue that can be fixed by galvanic isolation (aka 1/2 of a DI box), but sometimes those pesky USB cables simply catch up whatever interferences (which is why there's still some with those big HF-filtering blobs) - doesn't need a 200+ bucks cable to adress any of these, though.
In any case, regardless whether there's high pitch noise, interferences, whacky connections or whatever - one thing all these problems don't manage doing is to manipulate your 1 so it's 0.9526 only. Digital being digital, it only works at all as long as the 1s and 0s stay the same (ok, with possibly one exception, namely audio CDs where there's something such as error correction - but that's an entirely different story).