They could just do a rolling release.
Sure some admins may not wish to tinker with running servers too much, but part of the fun of the job is surely, to have some backup system and a quick flip over at some point.
I much prefer a rolling release style approach to operating systems, so many components update so often, that trying to maintain stability on older systems without updating to the latest and greatest is actually quite hard to achieve.
Still RedHat probably have a enough people to support a staggered many version release cycle.