can you opt out of a forum?

Fair enough, if you see the entire site as a local bar or something I guess.
However, I have seen on a number of other forums, the quality of the related topics mostly go down (snark remarks, members with knowledge going away, members having hidden 'beefs' with others), just because of a stupid conflict in an unrelated subforum.

Personally if it was my bar, I wouldn't want any of those tensions, people going out of their way to show their true colors and 'almost' bar fights ruin the stay of other 'bar'-visitors.