People talk about this as if it were a new thing. I remember a coupon expert lady in the 70s who on TV made a big deal of getting two large shopping carts of food for cheap. I figure if industry didn’t like this they’d have put measures in place to stop it over the last 40 years.
I see it as most people who use coupons don’t save all that much money, but it does entice them to try new brands. The big savers who you hear about are publicity for coupons, encouraging people to use them, and thus try new brands without really saving much overall.
I remember a story about a woman who clipped forty-some coupons from the Yellow Pages that promised $100 off a new car. As the coupon didn't state "only one coupon per purchase" she was certain she was owed a free car for her efforts. She didn't get the car (thankfully), but was exactly was her thought process? It certainly wasn't based on a system of fair play.
You are probably performing a patriotic service. By keeping inventories consumed, you assure that the factories will continue to produce more, people who work in those factories will be keeping their jobs a little longer, and so on.
What's better, in one's mind--to buy a lot now, or have to try to buy a little bit, later?