That's an absurdly reductionist viewpoint. You might as well say there are no people, only particular groups of molecules that can be fuzzily classified into humans.

It reductionist, but what makes you say “absurdly”? It is a matter of your personal choice what viewpoint to use and I was just commenting on the original point and the viewpoint provided.

I personally actually find this reductionism very helpful in seeing through these layers of constructs and making it my personal choice which ones to use, not just accepting them all as given.

subjectiveness across a large enough populace constitutes morality*, as much as those non-conformists may object

* "according to who?" you may ask: well, according to the populace, ultimately the only measure that matters

Viewed from this perspective, reality itself is subjective. Math doesn't exist, neither does physics or anything else we assume grounds us in reality.

It's a rejection of common reality and not worth engaging with because it's an argumentative dead end.

It's not binary; it is a gradient from actual perceived reality to very distant derivative concepts. For many people (e.g., those who do evil), these concepts obviously don't make sense, so I wouldn't even call it a "common reality." It's just a part of the subjective reality you belong to. If you choose to stay in your part of reality and not engage with those who are outside, that is your decision. It may be a dead end for you, but I'd also caution against generalizing.