Every time someone says “sound quality” is the reason they choose vinyl, we are back into “audio mysteries”. It took only 7 replies to the OP for it to happen in this thread. Maybe you didn’t get that far in your research of this thread before shouting “strawman”.
No you are just making some arbitrary criteria now for what you will call an "audio mystery."
Again, Leporello wrote "But many vinylphiles constantly argue as if this was a deep problem challenging our understanding of audio - "something that keeps vinyl alive". We never hear the basis and support for this idea, as the mystery has to be kept alive. But it just has to be talked about constantly, over and over again."
That's not true, at least of most of the conversations in this thread. There are all sorts of plausible ways in which the vinyl signal can be distorted vs the digital version, and plenty of been cited - everything from differences in mastering, in EQ for the master, in cross-talk, frequency response variations in the playback equipment, various forms of distortion picked up by the needle (the inherent imprecision of tracing vinyl grooves vs digital), etc etc.
All these can alter the sound, it's not like it's some Deep Mystery how vinyl can sound different!
And then, in terms of sound, it may be the case some prefer the effects of some distortions. (Some may not, and some may be fooled in to thinking they do...)
However, EVERY TIME someone makes reference to the ever-present claims of vinyl superiority in sound quality, you are quick to deny that such claims ever happened.
Like who?
Would you perhaps be referencing Atmosphere? I haven't agreed with everything he's written, but on the subject of the sound quality between digital and vinyl he made it pretty clear here:
"You can say how much better digital is and I won't argue that its better. I argue that its not better enough. "
In other words, digital may well be capable of better sound...but in terms of how MUCH better than vinyl, that is ultimately a subjective judgement call, and since virtually everyone who buys vinyl is also familiar with digital sourced music, his point is that it seems in practice out in the world, digital music doesn't seem to hold THAT MUCH of a sonic advantage to make people dissatisfied with the sound of vinyl. (Which can sound very good!)