considering he sells his own stuff in 24 bit as well it's probably not about the "humans can't tell difference anyway" thing. anyhow i don't quite get the point, it's like "wagner yeah, 5 points for the music, -3 because he's an antisemite."
Your example isn't really comparable, discogs is the place for finding out about cut quality as much as about music. Sure there could be a Holocaust music lovers site, where they rate nazi loyalty level. Needless to say, rating habits are differ, some are giving 1-stars to the best stuff and don't give much of a fuck, at least Mathieu left a note.
So what's wrong with 24-bit version then? Any non-humans?
I also guess he's point that selling 24 bit files more expensive than 16 bit is trickery.