[scandox]

I think choice is a big part of the problem.

We have too much choice about the people that we have in our lives and the basis of our interactions with those people. We're much more reactive than we like to admit - therefore having people in our lives who cause us discontent or even trouble can actually be a very good thing (within reasonable limits). However, once we have the choice (freedom of movement, a world of connected people just like ourselves, no dependence on "local" community) we naturally choose to exclude those people. We're engaging with or waiting on an ideal and painless social group.

It's somewhat analogous to being able to always choose what to listen to or what to watch. You never get any surprises. You are rarely challenged. The stimuli are weak.