Not really because people who are using RHEL in the first place are $BigCorp which run enterprise software (for example Oracle) for which you can only get suppo

Not really because people who are using RHEL in the first place are $BigCorp which run enterprise software (for example Oracle) for which you can only get support if you run on a supported enterprise OS. So we'd just run RHEL for the clients who needed these support contracts and used CentOS for everyone else to still have a homogeneous environment. With Debian I can't get this kind of support. So the options are reduced to Oracle Linux and SLES/openSUSE.