I don't do much HF work, so my comment is based on local chatter both simplex and on repeaters, but in my area the conversation is general good natured and friendly. Being human disagreements can and do occur, but those are few and far between in my area (Salem Oregon). Once you get to know a group you can also learn who the "know it all's" are, or someone who might be easily triggered, and take steps to not push their buttons.
Now that said I did have an opportunity to listen to a repeater in LA a couple times, and that was a totally experience, and not one I would want top have to live with. It seemed there were a lot of people on the repeater who felt it was their sole purpose to insult and offend as many as they could with little regard for operating standards.
So I guess my feeling is the level if civility depends a great deal on where you're located and the group of hams in that area, at least for the UHF/VHF bands.