Nobody runs AWS in their data center, but lots of people have a humongous and ancient oracle database or two running. Oracle Linux was forked from RHEL in the mid 2000s for this use-case.
I never had any interest in it because it didn't make sense to run Oracle Linux for the DB and some other distro on everything else, so we went with a more mainstream enterprise distro we could use for everything.
After they acquired Ksplice and ruined it for everyone else they have a better value proposition for it, since now they're the only ones who can patch kernel vulnerabilities without rebooting.