What I know from communities in life is that if an "undesirable element" moves into the community and remains unaddressed and is allowed to spread unchecked, the community goes into decline. And when the community decays... "quality" tends to flow out, leaving behind mainly the "garbage," with a few pockets of "goodness" entrenched behind tall barbed wire fences.

On the other hand, if the community stands together and runs the undesirable element out of town in tar and feathers. the community tends to not only thrive, but it strengthens the community bonds. Of course, this assumes a community where the majority share a similar vision for the community.

That's something I've seen too, and I think you're right on the ball with that. People who love to debate opposing sides of things will disagree. I personally don't like to debate just for the sake of winning an argument though. Some people who like to disrupt happy communities go in with that sole attention and hide behind "issues" as their shield. I always try to seek out those pockets of "goodness" you talk about.