In penance for the somewhat unpleasant tone of my last post, I offer this for your consideration.
A few months ago I was at an event where I exchanged pleasantries and made small talk with someone who is, shall we say, "not well respected" is some circles. I was later asked why I didn't just ignore the person. At the time I just shrugged it off, but here are a few reasons why I try to engage people, even when it takes some effort.
First, there's the decency/civility issue. The fact that someone else is a raging [insert preferred expletive/epithet here] does not give me permission to act like a [said expletive/epithet]. I realize that both "common courtesy" and "common decency" are almost as rare as common sense, but that does not excuse me from exercising them.
Second, just because someone is a [one of those] doesn't mean they aren't capable of intelligent conversation or providing a unique perspective on an issue. While it is generally more pleasant to learn from friends, it is often more insightful to view issues from a different perspective.
Third, the world is full of [them], learning to deal with [them] rationally is a necessity.
There certainly are some people who have crossed some line, ones who have established a pattern of behavior, or otherwise proven themselves beyond the range of civil discourse. At this point, avoiding them is usually better than arguing with them- you will either end up giving them exposure, making yourself look like a [you know], or both, if you mess with them.
Finally, there are some people who deserve to be called out. Just make sure you have examined the skeletons in your closet carefully and thoroughly before taking this step.
Now, if only I could follow my own advice better...
P.S. Don't believe any of this? OK, then try acting civil and consider it a social engineering exercise. The older I get, the less I care about motivation and the more I care about results.