As someone who used a lot of coupons for a few years, I always get a bit touchy when people whine and complain about couponers because for the most part, both the couponer and the cashier want the same result, but there's just so much misunderstanding and prejudice that it's hard.
I find that couponers tend to take a very defensive attitude right up front because they know if they get a clueless cashier, the cashier might mess up a perfectly legitimate transaction (because coupons ARE tricky and one mistake and suddenly you have lots of problems), so by being very firm upfront, they hope the cashier will just do what they ask and not take forever. That doesn't mean they're doing anything shady or trying to scam, but believe me when I say that one mistake would make the difference between saving or losing money.
I feel like if cashiers educated themselves on coupons beyond just the printed coupon guidelines and figured out why people use certain coupons a certain way, it would eliminate a ton of misunderstanding. When I first started to cashier, I had no idea what ocupons did and was really amazed to see people save money by just turning in a slip of paper. I went online, educated myself on coupons and how to use them properly, and started to use them myself. I don't have time nowadays to clip tons of coupons, but when I did, I saved a TON of money and I used them all properly; nothing shady.
I think the show "Extreme Couponers" has done nothing but perpetuate the misunderstanding and friction between legitimate couponers and retail workers, because just becuase someone uses a lot of coupons, does not mean they are crazy or trying to scam you. Sometimes, but 90% of the time they're not and they're just trying to save some money, and it makes it difficult for them when they are instantly branded "trouble" when they walk in the door.
Remember, Spot LIKES coupons. We make money on every one that is redeemed in our store. As long as all coupons are being redeemed properly, we move product, make a guest happy and we make money. What's not to like?
Sorry to rant; and I realize that you're mostly talking about the people who ARE coupon scammers. I just had to throw my two cents in there.