Doing so would reduce a player's XP by a ridiculously large amount. XP from grinding is not enough, and when grinding is the only way of gaining XP then ppl will get bored because none would spend a long period of time to go around and around killing monsters. Also, quests without XP are like cakes without cream, you can still eat them but please, who would ? I completely disagree with this idea. Plain wrong imo.
Oh and one more thing: Happy Lunar New Year ! This is the first day of the Lunar 2012 in my country and it is so exciting here !