The one thing that makes the argument bogus is its false premise, best illustrated by this sentence: "Let's take a look at operating systems with a modern, advanced, and robust graphics stack: Windows Vista and Windows 7."

Isn't there something conspicuously missing from that list?

While Windows 7 may be better than its predecessor Vista, which itself was a step forward in graphics architecture, why conclude that X needs to learn from them in particular?

I mean: if Thom Holwerda's thesis is "X.org, start your photocopiers," he could find better inspiration.