Re: But...
"So it's not Ubuntu at all - in fact it's not even Linux, if you're not running a Linux kernel. Shouldn't Canonical object to this misuse of their trademark?"
Correct, it's not running a Linux kernel but it is presenting most of a Linux API. Whether that constitutes infringement of the Linux name is a fair argument. As to whether it's infringement on the name "Ubuntu" - it ain't; Canonical are maintaining the "image" that's installed.