I'm pretty damn drunk and I only had to read the quote once to know that nowhere does anyone deny that MS paid for FF13 to be on the 360. Not even once.
Let's not mince words here: If you're looking at install bases (which is what is suggested) of course it makes sense to put the game on all systems. But what else is there to consider? Perhaps the reduced profits due to MS charging per-disc fees that wouldn't even come up on a Blu-Ray realease? Perhaps the fact that breaking a contract with Sony may potentially cost them millions of dollars? Perhaps the fact that the cost of porting such a large game may not be easily off-set by the added sales, since many people who woul have bought it on 360 would have simply bought it on PS3 instead?
The thing that's really obvious here is that the person quoted isn't giving you straight talk and is telling you to look at the obvious factors as opposed to considering all of the ones that aren't so obvious. And still, he never denies that MS paid for the game.