It really does depend on the person and the website. On Facebook I would not like friend requests from people I don’t know that well. Since I have contacts with my LPUer friends outside the site, I don’t care for maintaining the list onsite.
If you need points, go ahead and friend me. I’ll accept anyone. There’s nothing on my profile or anything anyway.
Just friend people. Let the decision up to the other person to accept or not. There’s nothing wrong with rejecting a friend request.