The Up and Leave Concept

Have you ever sat down at a restaurant and felt that you wanted to leave, maybe because it wasn't up to your standard (smelled bad, silverware dirty, etc)?

Well, the Chinese have no problem upping and leaving from restaurants, taxi's, toilets, you name it. I have been in the same situation a couple of days apart where we sat down at a restaurant, tea was poured, and someone didn't like the look and feel of the place, so off to another place. Another time it happened when we got in a taxi. We let the taxi move about 200m before we just opened the door and hopped out. Those offering their services are usually passive to the whole up and leave concept. I guess with a city of 20 million there are plenty of customers.

A bit confused...
I am still trying to understand where and when the saving face concept comes in. I think there is more of a social contract formed through people that you know and for those that you don't, then you don't have to really consider saving face. I just think it is funny that when conditions are more than smelly and the Shanghainese tend to make a stink about it quite easily (no pun intended)!