I have read the phrase "you are better than that Steve" a couple of times. Some could get offended. How I reacted was my responsibility. It's the Pygmalian effect. I assumed we could work to a meeting of the minds. I EXPECTED to. And we did.
That aside, most posters are well intentioned. We all cross over lines at some point. You let it slide.
The other class of posters, a few, arrive at message boards with malice in their hearts (if any). There moderation (ie-moderator) is necessary.