I would argue that the opposite is necessary, as a general rule of discourse: we should calmly and confidently talk about politics with anyone and everyone. We should be able to have discussions about things like taxes, the military, and technology, without resorting to screaming and shouting names.
One could make the argument that Hacker News is not a political forum, but I think explicitly discouraging political discourse is not healthy in the long run.
I don't think this is the problem.
The problem is the echo chambers people surround themselves with (and tech companies explicitly try to cultivate) and a slowly dying news media desperate for views, and whipping up outrage in order to get them.