remaining politics-free keeps us more level-headed about other issues, and because it avoids driving away the rather sizable population of rationalists who hate politics.
Is everybody here interested in everything here?
Probably not, so why shouldn’t the people who don’t like politics just avoid the political stuff (just like the people not interested in AI just ignore the AI posts)?
How could the LWers learn to discuss it rationally if you keep it out right from the outset? Isn’t talking about something rationally a skill that you acquire? Sure, most people have no idea how to discuss politics rationally (and furthermore have no idea that they have no idea how to talk about it in a rational way), but that doesn’t mean that they can’t learn. If you keep your kid on a leash all day because you don’t trust him to make the right decisions, what exactly would be bound to happen once you get distracted and drop the leash for a few minutes?