Yay! I've argued this a few times here and it's been, uh, perceived as low quality.

I think "objective quality" can always be re-framed in terms of fitness. "Quality" is just not anything the fitness function measures, so it can't.

It's hard to really make the case because of course there's something real that people mean, colloquially, and it's totally valid. Lots of things objectively have properties most people would agree show quality. That's where it is, it's right there!

But all those properties can be described without the use of "quality" by just reciting every fact about the thing. The only thing that will be left, the only thing you can't communicate that way, is what the person thinks about those facts.