@Mike: If you want to bus your own table in a fast food restaurant then go ahead, nobody will object. If other people, on the basis of your example, decide to do likewise, I'm sure nobody will object, least of all the management, who will then be able to mechanize the process of providing fast food for human feeders even further. I agree that demonstrating by example is decent behavior. Just don't think of it as 'civilizing'.
@Bucko: You are mistaken - it's not the case that 'no other country has this situation. Just in China' - but I'm sure that many Americans don't know this. Live and learn.
Note: I don't usually bus my table on the rare occasions when I eat in fast food restaurants here, but I don't throw things on the floor in restaurants either (although it's acceptable here, in most restaurants anyway) - and I would prefer that others didn't either. But that is just a reflection of my particular cultural background, nobody has appointed me an instructor of table manners for the people of Kunming - that sort of authority - or anyway, power - seems to have been appropriated by the state. Does the state have a policy on table-bussing yet? Do you want them to enforce things like that? Are you obedient?

Some of the cultural relativism on this thread is a bit much. Excessive reluctance to cause offense can lead us to deny what is staring us in the face.

It shouldn't be controversial to say that throwing table scraps on the floor is disgusting. Similarly, the Chinese are right to say that's it's disgusting how we eat burgers and sandwiches with our bare unwashed hands (not that that stops me... ). So it can cut both ways.