I'd suggest that the point of avoiding political discussion is not just because it's unpleasant or divisive. In my eyes, the problem is that politics has so much implicit back-end that it cannot be usefully discussed on an internet forum. In the several paragraphs (at most) that we write to another, we convey so little while disagreeing on so much. Besides that, there's the issue that we spend much of political discourse not actually explaining ourselves, but rather signaling to others what camp they should put us in.
My wife and I, on several occasions each day, will say to one another, "we're describing two different things. We need to take this discussion far deeper, or end it altogether." That's the person with whom I talk more than any other person, and we aren't on the same page on divisive issues tens of times each week.
Without unpacking an issue to a level far beyond the length of forum posts, we cannot possibly hope to be on the same page in our discussions here when they veer into politics. It's better to favor the format of discussing interesting issues about which most of us are unfamiliar. That way, we get fresh eyes thinking about the issue, more polite discourse, and a more educational experience.