I don't see how this is political. In that link he presents actual problems that have arisen from non-blocking versions. I'd call that a technical justification.

I don't necessarily agree with his justification, but that's also a difference in technical opinion. The only way I'd fault him is if I can come up with a an approach that addresses his concerns yet he still refuses to accept them.

Full disclosure: I've actually interacted with him on a few occasions. IMO calling him risk/change-averse would be an understatement, which partly explains this stance. While at times frustrating for us, this is exactly the quality you want in someone maintaining such a critical part of the kernel.