My commenting policy is pretty straightforward: say anything you like as long as it is not racist, sexist, ad hominem attacks on other commenters or the host, or thread-derailing, which includes irrelevant references to off-topic points, straw men, or red herrings. I welcome opposing points of view as long as they are presented in a civil manner and with respect to the other readers. (By the way, that also applies to other commenters responding to those points of view.) In other words, treat this site as if you are visiting someone’s home as a guest. If you track dirt on the carpet, kick the dog (or cat), and complain about the food, you’ll be kicked out and not asked back.
I don’t expect a chorus of supporters all agreeing with me, but I do expect respect, both for me and the other readers. I think I’ve earned it.