"I also worked in retail and have endured the rudeness of customers laying or throwing their money on the counter to be picked up by the salesperson. However, they always have their hands out to receive their change into their hands.
"Wouldn't they feel insulted if we, in turn, tossed their change on the counter for them to gather up like birdseedfi People of different ethnic origins sometimes feel that it is a direct insult to them, like they are afraid to touch the clerk's hand. Everyone should practice handing the money to the person collecting as they would like to be handed their change." -- Arizona Salesperson
Search for it online. You will find nothing but people complaining that it is rude/disrespectful. Like most of the new internet sins, it was more than likely not a huge thing until one person complained and it started spreading. Now it is almost a mortal sin, but like buying Indulgences from the Catholic Church, for the right amount extra they will not say a word.