I've always had criticisms about Apple for different reasons. This isn't one of them. Apple is well known for trying to bring product to niche markets, and the fact that OSX isn't used in a manufacturing environment only verifies what everyone already knew. All this article affirms is that Windows is the most ubiquitous workstation OS in the corporate world. Many Apple users would likely not want to get reminded of that, but hey, it's a simple truth.
In any case, it absolutely was a PR blunder. You won't see a Chevrolet commercial with someone in the passenger seat looking at a Ford brochure. You don't take a picture of the Mac Pro product line, arguably one of the most expensive workstations today, and let people think that you include software that you wouldn't trust to manufacture them. It's a perception thing.
I agree with jpiniero though. Apple has done a horrible job getting Mac Pros made. They were never expected to move large volume, but getting them to market has been very slow even by Apple standards. There have been criticisms of them filling third party orders over filling direct orders.
