Because it makes me less happy.
That’s it. There’s no other deep principle or reason. This is also why I occasionally do read them. It (rarely) can be enjoyable.
I don’t dislike commenters or discussion. For some reason it detracts from my enjoyment of life to read comments. Maybe that’s a shortcoming of mine. Who knows. All I know is that my life is better and I get more done and am happier when I completely ignore them.
It’s freeing to remind myself that I don’t owe responses to critics or commenters. Realizing I can ignore them actually makes me a little more likely to occasionally engage them. But it’s still a rare occasion.
Life’s too short to do things you don’t like doing.