Theoretically, politics is defined as anything where decisions are made to solve conflicts. However, this is 'broad politics'. A much more common interpretation of politics adds the requirement of it not only being a single, but regular occurrence or rather the main job of someone. Ergo, politicians of a country, or part of it, and their decisions .

Replying "everything is politics" to someone expressing they do not want to talk about politics is like telling someone their offspring cannot be called "kid" anymore as they are over 18 now, after a mother cried that their "kid died of cancer". It's technically correct, but you're a major annoying asshole or just plain stupid to persist on the meaning that was not intended.
As I do not believe there are that many people with a room temperature IQ, in C, or maybe autistic people for that matter, which of course are not responsible, only one explanation remains. If you, or anyone else repeating this pattern, is not an asshole, they should just shut up, or argue for politics if they really want to discuss this topic. A much better solution would be to move to politics only instances tho.