“Arguing with strangers online” on its face sounds like a categorically worthless thing to spend one’s time doing, and it’s usually framed derisively. However, I enjoy it in some respects, and derive value from it. When you have hordes of people out there hell-bent on challenging and scrutinizing your every point, no matter how ancillary/trivial, it mandates that every point you make be completely rock-solid, whether logically or factually. And it’s a more stimulating activity than sitting around watching TV.
My old blog had an “About comments” section that was pretty much what you said only on “Don’t ever read the comments” sanctimony. I should probably bring it over.