sometimes there's an item in the AH you are interested in but may not want to bid on right away, you may not have enough crowns at the moment or you would like to wait until the auction is closer to ending, having a watch/track option would be nice so you can keep up with the status of an auction without having to actually place a bid right away.
wat they should do in my mind is that and add a mini AH (for wen ur in clockworks) so u can c ur bids and if u need to bid more u can do it wereever u r