It's not. You can freely talk about other topics. In fact, talking politics is probably safe as long as you are not too loud. I think it is the same for all countries I have lived in. Talking about politics is always taboo.
and
"Talking about politics is always taboo."
Hahahaha. That's not the airtight argument against "a subtle way of saying keep your mouth shut" that you apparently think it is.
Not around where I am, at least withing the various circles I talk to. It can be hard to avoid, even. (to be fair, I live in a city which is relatively an outlier on the political spectrum compared to the country as a whole)