I've haven't heard of any difference either. Some places don't even mix the sugar with the grounds, because that reduces the amount of coffee you can put into the machine. But, you have no more chance of convincing him that prying a glass carboy out of a believer's lacerated hands.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk