Whataboutism isn't new, nor is it intellectually dishonest to point out when it's being used. Soviets started using it during the cold war era, and it's still in use as a deflection tactic today.
You are absolutely correct, however I would argue that it has only relatively recently entered the common HN lexicon. The vast majority (~675 out of 704^) of comments using it here in the comments are < 2 yrs old.
Admittedly the first comment on HN that used the term is 7 years old, but that comment [0] predates the creation of the wikipedia article (frequently trotted out when invoking the term here) by about a year.
As an aside, I'd love see a dataviz app that shows the lifecycle of terminology and memes that thrive in various internet discussion boards.
