Does it not stand to reason that more memory devoted to textures will, all things equal, give a better looking game? Or to put it in another way: if you have two development teams with THE SAME SKILL, which one is more likely to look better? The one with more memory devoted to textures, etc, or the one less devoted to textures?
Look, your argument would be true if what you said was "larger game size does not ALWAYS correlate with quality," but instead you said "larger game size DOES NOT correlate with quality." The problem is, of course, that the evidence contradicts your argument, as it is stated. Generally speaking, these other sports games are simply better than Madden. Do you deny it?
Particularly when it comes to NBA 2K, the comparison isn't even close.
You think file size has NOTHING to do with this?
I'll tell you right now a game looking this good requires more memory per unit area/volume than Madden does; more memory per unit code with lighting, etc. Not even a possibility that it doesn't, in all reasonableness. Frankly, NBA 2K Next Gen looks like it was made on a Next NEXT gen console in comparison. What a coincidence that it is more than twice as big... definitely game size has nothing whatsoever to do with that...
I mean, come on, man. You can't really believe what you just posted.