Because as you imply in your other comment, MtGox is not deemed as trustworthy exhange by many. It is good that Bitcoin doesn't rely so much on it for now. Aft

Because as you imply in your other comment, MtGox is not deemed as trustworthy exhange by many. It is good that Bitcoin doesn't rely so much on it for now. After all, MtGox is not Bitcoin.