Why would it not? You still pay a price for putting up item on auction house. Just a clever use of game mehanics.

Lot of people use it for storage. Sometimes you run out of space but do want to keep the item, so you put it for very high price in AH. You do pay the fee for putting it there as normal.

It is a great method for short term storage. If you were to keep items in the AH 24/7 for a month it would cost a lot more than storage at the tavern, but if you just need a few spaces for a few hours it works out great.

And it's not alright for some players to use AH for temporary storage... It's alright for all players to use.