From the printed questions the OP saw at the register it appears that the bone-headed idea in the original thread was likely the result of corporate management. So it occurred to me that starting a discussion on what people really want from their grocery store(s) might be worthwhile.
(1) Lower prices without tricks like cards or contests; just price the food as low as you can without sacrificing quality or spending time and money on tricks.
(2) More cashiers at rush hours. You know when they are so put more people up front at that time. Also, schedule more packers.
(3) Have several specialized lanes: one for 12 items or fewer; one for people with more than two coupons, etc.
(4) Get store management to be more involved by getting to a register or customer that is having problems fast. Don't wait for a call from the cashier. If management, who should be watching the registers closely, sees someone get in the wrong line--someone with a full cart gets in the "12 Items or Fewer" line--they need to handle it immediately too. And if that customer is unhappy, well, so what. Make everyone else happy and let the fussbudget deal with her unhappiness.
(5) If you offer things that people pick up for a meal--breakfast on the way to the office, lunch, or maybe one entree on the way home--how about offering a special register just for them.
(6) Every single person in corporate management needs to spend a minimum of one month every year working the register and/or floor--and not in a management capacity. They should also be required to shop for themselves (and their families) there, preferably at rush hour.