Humans lost their fur because of he path our evolution took. The most basic form of human hunting is endurance hunting (i.e. literally chase an animal until it collapses from exhaustion). We happen to be pretty good at that because we lost our thick body hair. Endurance hunting means you build up a lot of body heat over a looooong time, so the issue was never staying warm, but staying cool. We did that for long enough for it to have an effect on our biology, and it was too late to go back once we developed more advanced hunting tools and tactics.
Jesus, do some anthropology before you start to bang on about human evolution.
This post has been edited by Robinski on Thursday, Jun 28 2012, 13:29