You seem to have a problem with social networks in general ...

As for I gotta say, I'm a little offended by your audacity, because you're essentially asking me to categorize every single person I've ever had an email conversation with as a friend or a non-friend

No one is forcing you to categorize anyone, these are suggestions from your contacts you can not circle them at all if you don't want to, as for the categories they range much wider than "friend" "non friend".