I think there's an inherent difference between the kind of kink-oriented discussion elsewhere on the site and the concept of political discussion.
Kink is a "well, it's not mine, but it doesn't hurt anybody, so if it makes you happy"-kind of thing if you disagree with it -- at least with this group, because everyone's outside the norm as far as society's concerned, so there's less judging of what's really personal preference and doesn't impact others.
Politics, on the other hand, is inherently an "I'm right/you're wrong"-topic. Political beliefs impact political decisions -- and the political decisions of individuals impact others. As an example, a political belief in nationalized health care in the US impacts me, despite the fact that I disagree with it and think it'll harm the country.
Getting pissed on isn't my thing, but other people like it and them doing it doesn't impact me or harm anyone, so why would I criticize? But nationalizing health care will impact my standard of care and personal economics, so it's a different mindset.
Political debate is inherently about attacking/defending positions. That's entirely healthy and appropriate, since if someone can't defend their positions, it's probably a sign that they should think about it more.
I was once extremely pro-death penalty. I went into a conversation with someone with that belief and came out an hour later with a "holy fuck, what was I thinking"-moment. I got there because I was forced to defend my belief against his attacks and arrived at the point where he'd asked a question that I simply couldn't answer within that belief system.
If he'd simply said "well, you're entitled to your opinion, but I disagree", then I'd have gone about my business without changing that belief -- he didn't. He attacked my position, viciously, in fact, because he thought my position was wrong, immoral and harmful to others. In the end, I had to agree that he was right -- and that act of questioning myself because I couldn't defend myself to another made me a better person.