One word. Law.
As Florian Mueller has pointed out, many times now, Google faces an immense potential liability from Oracle's copyright-and-patent suit. The suit isn't against Android per-se. It's against Dalvik, the Java Virtual Machine (JVM) written to run Java-based applications. The Google legal team did not do their homework before letting this semi-proprietary thing into the wild, and Oracle may justify its purchase of Sun with one law suit as a result.
While Google and Oracle are both part of the Open Invention Network, the patent consortium designed to protect Linux, the suit is about Java, not Linux. The OIN has not, and will not, interfere, even though OIN head Keith Bergelt has made noise about wanting to protect Android in the press.
Google can't do anything about what has already happened, but it could reduce the potential of future damages by merging its Android code base into a Linux the OIN is sworn to uphold, namely Meego.
Microsoft is slowly absorbing Nokia, which is actually a recommendation for this move. Nokia is going to become a Windows Phone shop. This makes Meego an orphan, but one with powerful allies in the OIN and the Linux Foundation, where it is an official project.
The Linux Foundation has been dissing Android, in a desultory way, through its Wiki, but that does not mean the two could not be merged through a roadmap. Google would be paying most of the costs, and it would lose some exclusivity, but a careful negotiation with Linux Foundation head Jim Zemlin could adjust Meego rules in such a way as to prevent fragmentation, which is why Android is unitary in the first place.
Android market share peaked in March, and it's now headed down. The Apple iPad has something to do with it. So will Microsoft's absorption of Nokia. But what's cooling the heels of Chinese device makers, more than anything, has to be the legal situation.
By capping the potential Oracle damages, by merging the code base under the Linux Foundation, Google could protect what it has and at least put a line under its biggest legal headache. It would be the biggest contributor to Linux' most important project, regaining some of the goodwill its more proprietary moves have lost. Any loss of control could be minimized.
So tell me why it makes no sense for the robot to shake hands with the penguin?