This is why I despise using coupons (or gift cards, for that matter) in restaurants in general. Coupons, like it or not, have a distinct stigma associated with them that never nets you a pleasant restaurant experience.

More than anything else, I think the OP is complaining about restauranting with a coupon/gift card rather than utilizing Groupon, specifically. That said, he's correct that the model is broken for this very reason.