Red Hat pays the salary of a couple kernel developers, backporting security fixes is a pretty big part of their job. Keep in mind, RHEL/CentOS 7 doesn't even us

Red Hat pays the salary of a couple kernel developers, backporting security fixes is a pretty big part of their job. Keep in mind, RHEL/CentOS 7 doesn't even use something newer like 4.4 - it's still on 3.10 because Red Hat guarantees a stable kABI throughout the lifetime of a release