It's really sad, because it's not only good restaurants that do the Groupon thing. It can be a good way to advertise your business in addition to the standard (boring) ways.

Any restaurant that treats their customers like crap because the customer uses a deal that the restaurant approved is... Well, rude. I don't have much use for rude restaurants. For a lot cheaper, I can cook the food myself, and it's probably as good. Worse, the time spent is about the same, too! And cooking can be fun.

So in the end, what does a restaurant offer me? New dishes, and good service. Most restaurants don't have the former, so that just leaves good service.

The restaurant in this post failed at the only thing they can offer their customers. And all because they made a bad decision. (I'm assuming they think it's bad because of their actions.)

I'm not a Groupon apologist. Some of the tactics I've heard lately are downright dirty, and detrimental to both the restaurant and Groupon both. But it's not inherently a bad thing.