"kernel tracing is _very_ valuable to Linux *users*."
Isn't this exactly what the article says Andrew Morton is resistant to? If it's ultimately exposed to the end-user, then it will have to have a set of stable user-space tools to gather the information, which means it will essentially be a part of the ABI that has to be maintained, or which people will complain of if broken.
The Xen hypervisor has a binary-only static tracing facility that I use extensively for my development. The particular traces change on a regular basis as the code evolves; trying to maintain the same interface for user-land tools would be basically impossible. As it is, before each release I have to go through and make sure that all of the traces I need are still there and haven't been broken by someone else. I think it's worth my time as a developer dealing with the instability. But I wouldn't want that promise exposed to an end-user.