Need proof? In January, Microsoft shipped the first security patch for Vista. It was for the WMF (Windows Metafile) hole. You know, the one, that my security guru friend Larry Seltzer called, "one of those careless things Microsoft did years ago with little or no consideration for the security consequences."
Good job of cleaning up the core operating system, Microsoft!
Well, first, the WMF vulnerability was never part of the core operating system, nor is it associated with the "kernel" in the way that you imply. It makes sense that rather than put early resources into rewriting WMF support for Vista, MS incorporated the existing WMF functions, and then had to patch them.
The rest of your points seem to boil down to the same old: MS should have done this years ago. That might be true, in some relativistic sense, but ultimately it's not even a remotely useful point of view. MS had to deal with the realities of business and an installed user base. They made the decisions they made, and they are where they are. Comparisons with niche operating systems like Linux and BSD are, frankly, silly.
D'oh, I also didn't realize that was an excerpt from the article, and not OP's commentary on it. Post-n-run indeed.