Yes but again this is an argument against the complete rep system not promotion based on reputation. How many people's friends are going to register to a random board just to get a friend a minor promotion.
The point is, if the reputation system is any use at all, then it should be used for purposes such as this. Otherwise its entire existence is totally pointless. If the reputation system works succesfully, as it does on my board, then we should be able to utilise it fully.And would remove the temptation to reply to every post with inane smilies and comments that add nothing to discussion.