thro7654

Whataboutism is about hypocrisy.

Argument: X is bad because Y. Counter: But Z is also bad because Y and I don't hear you saying anything about that! Conclusion: So X isn't bad.

E.g. the typical Soviet whataboutism:

Argument: The USSR doesn't respect human rights and that's bad. Counter: A u vas negrov linchuyut (but at your place, you lynch negroes). I.e. the US doesn't respect human rights either. Conclusion: So the USSR isn't bad.

The mere presence of Z does not invalidate the argument that X is bad because of Y. It's irrelevant, which is why tu quoque is just that, a fallacy of relevance.