What is RHEL compatibility so important and why is it always such a hot topic?
Other open source competitors like SUSE and Canonical have much smaller revenues, so Red Hat could be seen as having a bit more influence over Linux's overall direction (they employ a ton of devs, they have a ton of resources). Case in point, the systemd controversy.
There's also a historic argument that one cannot trust FOSS in the hands of any corporation, but we start getting into more philosophical and nearly-religious debate at that point.