This is a pretty well-constructed argument, despite the unnecessary invective at the end. It took me a while to figure out how to rebut it. (Therefore I upvoted you to counter expected downvotes.)
But I think it goes like this: there's a difference between not caring about something for a week and not talking about it. If, as you assume, for most of HN politics is "things that affect other people", then the primary objective of political discussions on HN should be to convince those people - not, say, to make the minority which is affected feel validated. My impression is that when people who are affected by something go and read a ton of Very Strong Opinions put forward by people who aren't, the result is usually more invalidating than validating; validation is important but is a purpose better served by more focused communities. Now, when it comes to convincing people, a constant barrage of discussions on the same topic is probably more unhelpful than helpful; at worst, pausing discussions for a week (which gives them time to reflect) is unlikely to be very harmful.
Notwithstanding that, some people may perceive the idea of taking a break as invalidating, because it reminds them of a generalization about the community (not affected) which does not apply to them. However, so far as it's an accurate generalization, this seems like it can't be helped. I suppose you could argue that it seems more accurate than it really is, since marginalized people are present but silenced…
Anyway, I think "things that affect other people" is an oversimplification to start with. A lot of the specific political topics people like to discuss on this site, like encryption/surveillance, have fairly little direct impact on pretty much any of us; others, like the economy, affect all of us to some extent, albeit some more than others.