Well, speak for yourself. I, and many of my Facebook friends, have gone on deleting purges before and I've never seen that reaction. The main fear seems to be upsetting the acquaintances that you unfriend.

If you're going to spend time on Facebook at all, it's worth the time every now and then to make the time better spent. They even have a page called "edit friends" where you can just go down your friends list ticking the X button to unfriend them.