Canonical doesn't really compete in the traditional enterprise space, we're a cloud company, so you'll see us on AWS, HP Cloud, etc on the public cloud side and OpenStack for private clouds.
Although no doubt there are Ubuntu servers in the cloud like that, this summary seems unrealistic:
> we're a cloud company
Then what's up with Unity and the push towards a common interface? Cloud servers are not phones/tablets.
And BTW, I think Canonical (and Microsoft) pushes towards common interfaces have been huge steps backward, no matter how well intentioned, so given that, I wish Cananical were just "a cloud company".
Just spit balling here but, in general enterprise OS selection is driven by software requirements. And the requirements, for enterprise linux software, tend to be RHEL or Oracle Linux... i.e., not Ubuntu Server.