Oracle does jack shit for Open Source software, including the Linux kernel. There is nothing useful for Red Hat to incorporate back from the Oracle kernels.
This is clearly a move to counter Oracle, and I can't blame them. Oracle has more money than god, and a willingness to do anything to win. They're rebuilding RHEL, rebranding it, and extracting money from their sizable corporate userbase for it...money that probably ought to be going to the folks who actually built the distribution, and the people who build the underlying software (Red Hat contributes more to Linux and Open Source than any company of its size, by a significant margin; Oracle contributes effectively nothing, in comparison).
That may be changing...Oracle has hired on at least a couple of reasonably well-known kernel developers (Chris Mason, for one). But, for now, Oracle is leveraging the development work of Red Hat far more than Red Hat could possibly leverage anything out of Oracle. Oracle just isn't a team player in this regard, and it's not built into their culture to become a team player, as far as I can tell.
Oracle can certainly deal with it. Many problems are solvable with sufficient money. I just think Red Hat is trying to make it more expensive for Oracle to rebuild/rebrand RHEL while still remaining dedicated to supporting the upstream. I don't know if this is the best way to achieve that end. But, I have a great deal of mistrust for Oracle, while I feel pretty good about Red Hat. Oracle's handling of MySQL is not making me feel better about them, either, while we're on the subject.
It helps RedHat focus on the bugs their customers care about -vs- bugs non-customers care about.
I think that's a bit of an overstatement. http://oss.oracle.com/projects/btrfs/
The thing is, Red Hat is free to grab Oracles changes and incorporate them back. Tit for tat and all that. This policy change surely must have come from upper management. Real programmers know it is no serious problem for Oracle, only an annoyance for everyone else. It is also very much against the spirit of the GPL.
I respect Red Hat for all the open source work they do but this change is lame. Piss a bunch of your most loyal customers and advocates off for no real gain. Sounds like a great plan.