You make a fair point, however when you work for someone, that is your choice. To shop at a business is your choice. If you do not like a business, do not work for it and do not shop there.
Stealing from someone is stealing from a person who took time to produce that item. In the case of s store, the store had to buy the product from a distributor.
So theft is still inmoral. Is theft greed? Yeah it could be and in most cases its greed and selfishness. However the thief in most cases can buy the item but chooses not to.