This has little to do with getting Linux on mobile. Maybe it's the motivation for some. But not the driving aspect.

Samsung wants Tizen to gain back full control of their platform. Canonical wants Ubuntu Touch (and Mozilla Firefox OS) because the PC is getting less important for consumers.

> (And please, stay away from Java in your next mobile OS. Among other things, you will ward off those of us, developers, who let's say are not neutral wrt. to certain programming languages. Edit: make Java optional if you wish.)

Neither of them is based on Java. Tizen and FirefoxOS are (sadly) JavaScript only. Ubuntu Touch supports JavaScript/HTML5 and Qt (JavaScript + C++).