Canonical is not a public company and afaik they haven't turned profitable yet. Besides they
have already asserted that their desktop is a means to get a foot in the door and sell it to
the enterprise eventually.
http://www.news.com/A-Linux-start-up-on-the-path-to-profi...
Besides Red Hat continues to invest heavily in core desktop components.
http://fedoraproject.org/wiki/RedHatContributions
I guess that wouldn't happen unless there is belief that there is profit to be made.