Actually, yes, there's a basis for it (and since I don't remember it exactly, I'll be paraphrasing) --

Using a higher pressure in back is a no-brainer since the rear tire carries more weight, but I don't think that's what you're talking about. How he arrived at determining pressures by size and rider weight was to ensure that the tire deforms a certain amount. Like I said, I can't remember for sure, but it's something to do with getting a good shape to the contact patch, maximizing the contact of the center of the tire on the ground, while neither overinflating and losing grip nor underinflating and allowing pinch flats.

I've been experimenting with pressures on my road bike, and that formula works out just right for me. If I inflate to a higher pressure, the ride gets harsh and the handling gets more skittish. At lower pressures, the ride is more compliant, but sharp bumps seem to hit harder (just not enough air support to prevent bottoming out the tire), handling is a bit squidgy, and I feel like I have to work harder to maintain my usual speed. Using pressures as recommended in that chart gets me a good balance of ride quality, handling, and efficiency.