Why wouldn't they switch to Debian instead? Their emphasis on stability matches that of CentOS more than Ubuntu, or at least did.
Canonical and RedHat are paying the salaries of the people steering the direction of Linux as a whole. They're forcing you to choose between the two.
That's pretty weak sauce even compared to the five years Debian and Ubuntu offer. And Debian actually supports all their packages, unlike Ubuntu which tricks people into installing unpatched garbage from 'universe'