Assertive personality? or ...

I had a opportunity to join a drinking party of my husband's department. His boss, colleagues and some spouses (otherwise known as drivers) got together at Stone Brewing World Bistro & Gardens. We had a good time with beer & wine in laid back atmosphere :)

After dinner, the waitress came to us, cleared off the table, and asked in a casual manner as they were supposed to do so. "How was everything? Was it okay?" One of ladies from our party replied politely, "Your food was unusual for us!". Although I did not think their food was terrible, her word "unusual" obviously connoted "It's not our favorite", but I believe it's okay for customers to be candid and say straightforward to some extent.
However, believe or not, the waitress's reply was ...."Our owner doesn't expect everyone to feel that the food was 100% tasty. He embraced an innovative approach and wanted to let people know what the developed food was." She dared continue "Hamburgers and Pizzas are not only the food, and there are much more the American haven't tried and should get to know".
I couldn’t believe what just came out of her mouth. This sounded too rude for me. If it happened in Japan, the customer would have dished out the waitress and she would have been given the boot. But the lady murmured in a courteous manner.“You should put some paper to have us comment on it!” and her unresisting behavior subsided the mood as if nothing happened.

I realized afterward that they were saying, "We're not health nuts, but quality nuts!" on their card. Before upholding it, shouldn't they be decorum nuts?