The fact that "Politics is the Mind-Killer" doesn't call for a blanket ban on political discussion doesn't mean that a community norm against nonessential political discussion is necessarily a bad idea. Now, I would say that roystgnr's jumping the gun a bit here -- the OP's tied pretty closely to heuristics and biases research, and avoids explicit color politics -- but I'd rather we engage the norm on its own terms rather than in terms of its relation to Eliezer's post. After all, we're hardly bound to take Eliezer's word as gospel.
Ok sure I can agree with this, even if I think Overcoming Bias/LessWrong used to be more interesting when we stuck to EY's proposed norm. But come now you must know of what I'm talking about when I say:
It has now been applied to everything from biology, sociology, sexuality and even recently to religion.
There has been overreach. Worse politics as the mindkiller is now being used as a political tool.
The last point reminded me of speculation from the recent LessWrong article Conspiracy Theories as Agency Fictions:
Before thinking about these points and debating them I strongly recommend you read the full article.