Maybe I'm_ missing the point here - but aren't you saying exactly the same as the poster you're replying to?
Experienced NT admins know NT, experienced Linux admins know Linux. Some of them may_ also know the other of the two systems, but it doesn't necessarily follow.
As Jason Hiner observes in the article, if you're moving from NT to Linux, expect some retraining costs. The same would be true of moving in the other direction - I suspect if Jason were coming from a Linux background and not that of a trained and experienced MS admin he might find NT/2000 just as hard to set up, and at least as time consuming as Linux.