I may have said something such as "Oh, what color or kind of ruffle are you adding?" The purchaser's answer would have clued me in and then I might have replied that I once had to scrounge for matching fabric when I was in a hurry and forgot to add extra inches for shrinkage , hems, etc.
Also, most retail stores hire at minimum wage. It's about the bottom line. They just need a body in the department. Well-trained folks won't work for those wages. One thought, at least the guy from automotive or sporting goods is not sent to the fabric table to cut your fabric! No need to mention that retailer's name! I refuse to buy if they won't let me cut my own when that happens.