I agree.

I think the only time quality might be objective is when there's a planned "ought", like a required feature that needs to be implemented later.

From that perspective, the "quality" could be measured in how easy it will be to implement that, in a "total effort" sense (subjective I suppose), where "low quality" might require a whole rewrite of big sections, where "high quality" would have the required stuffs in place (maybe abstractions, or maybe even placed where spaghetti would fit nicely) to make it "easy".