Just to acquire something someone else likely obtained fair and square with his/her hard-earned money? Does a domain name have to show content to be "used" anyway, especially when there are other plausible uses for it like email, DNS server, etc.?
There are measures to handle domain squatting of trademarks. Beyond that, nothing much except maybe some people wanting to selfishly take things that don't belong to them, just because they can't seemingly have their way with those having what they covet.