Pride goes before a fall.

It´s definitly fear. Or do you know a different explanation for such a major malfunction of good sense. Andrew Morton went as far as:

He didn’t mince words. “It’s a great shame that OpenSolaris still exists. They should have killed it,” said Morton, addressing one attendee’s question about the possibility of Solaris’ most notable features being integrated into the kernel. “It’s a disappointment and a mistake by Sun.”

I have an idea, how it came to this comment. I assume he was asked “When do we get ZFS and DTrace for Linux” all day long and at the hundreth time, he lost his nerves.
PS: Mr. Morton, until the developers of SystemTap don´t understand the ideas and concepts behind dtrace, SystemTap won´t be anything near of dtrace.