To some extent, the point that we have politics as a way of resolving issues without bloodshed is valid: modern politics in many ways is an improvement over the alternatives. But that doesn't by itself make politics a good thing or make politics less of a mind-killer.

The point is, it's not at all clear whether we can do any better. The "politics as a way of managing conflict" POV elucidates several features that do set apart politics from ordinary deliberation, which is the domain LW-style rationality is most directly applicable to. (Such as concerns about fairness in political processes, a focus on adversarial argumentation even in factual matters, a need for compromise and creative open-mindedness in order to mitigate value conflicts etc.) For the record, I think that this - "can political discourse be improved along rationalist lines?" - is very much an open question; however, LW is most likely not the best forum for addressing it, given that such a focus would conflict with its well-defined goal of refining the art of rationality.