I've thought for a while that the ejection of Facebook, the probably ejection of Google, etc., is all part of a face-saving Kabuki to give Chinese companies room to grow, now that Facebook and Google have proved the utility of their respective functions to large groups of people.
For example, without Facebook as competition, such functional facebook clones like 51.com, xiaonei.com, and chinaren.com are growing quickly, keeping both the service and the economic benefits of the Facebook idea within China's borders in a classic case of economic protectionism. Yes, the government can exert more direct control over them than they could over facebook, but at this point, that's kind of the icing on the cake.
Without Google as competition, Baidu (www.baidu.com) has that much more room to grow and take more tech jobs from the Indian economy and give them to Chinese. Yes, the government can censor more, but again, that's icing on the cake, since there are many other ways to maintain censorship and manage the population. Simply keeping things in the Chinese language and managing the traditional media go a long ways towards maintaining such control anyway, automatically excluding foreign ideas while keeping the frames (and therefore the conclusions) of major debates under control. Such a condition is not "censorship" in the strict use of that word, but this is the system used by Western governments to control discourse, even though they lack the self-isolating features of the Chinese language, so there's no reason why it shouldn't work here in China.
Examples of Western "censorship" can be found at sites like www.projectcensored.org, by the way. My point, then, is that, while censorship is important to the government, there's more than one way to accomplish it. There is only one way to provide economic protectionism, which is to divert more economic activity to local businesses, whether that be through tariffs, governmental spending, or what have you. Therefore, economic protectionism seems to me a primary reason for this kerfluffle, even though censorship may, of course, remain as a secondary reason.
This Google exclusion is all of a piece with the general economic protectionism with which China has been irritating ideologically "free market" types for a long time.
The current arguments over principle, then, can be viewed as a dramatically-colored veneer allowing both sides to save ideological face when the inevitable market protectionism takes place.