You're conflating two different things: actual political discussions and meta-political discussions focusing on e.g. "rational defenses" when it comes to politics. You're justifying the latter, but people downvote and shun the former.
The latter, in theory, could be done without any content from the former, although frequently people fail to pull that off. E.g. you could have a discussion about how and why political discussions tend to fail at rationality, and what could be done about it, without opining on any political issue. Such a discussion, I conjecture, would not attract the usual "political" downvotes and objections.
There is a tendency to downvote articles and commentaries with a political subtext with a remark on how politics is the mind-killer. I completely understand that nobody wants his mind to be killed, however, I disagree on the employed methods. I don't think anybody can really afford to ignore politics. It's a fact about any group of even a handful of people. Thus instead of shunning politics I think it's better to build one's rational defenses. Understanding that politics is a problem is only the first step. If you stop there, there will always be a big part of life where you are not rational. Therefore I suggest that, as long as it doesn't get out of hands, there should always be room for political discussions if not on the main site at least in the discussion section.