You're all morons. People like to use different characters for different scenarios. He went Peach because he thought he would do better in that situation with her. It doesn't make his Peach better then his Fox, and him going Fox on Kage instead of Peach doesn't make his Peach better then his Fox >_>
I remember at Mass Madness PC telling me that Shiz wrecked his spacies and he hated fighting technical spacies with his own, he was probably just more confident and comfortable with Peach against the Falco. I dunno if he still goes Peach against Samus or if he's using someone else for it now, but same thing there.
Some players are better at some match ups. The chart is harder to look at because when you try to evaluate a match up it could be like "well X player is bad against Sheik with Fox and he got *****..... Well Y player ***** that Sheik with Fox". The chart involves theory crafting taking what would be an optimal play style for a match up and seeing what the other character can do (if anything) to counter it and win.
Like the Ice Climbers can do blah blah to Fox (chain throws, combos, beating ground approaches with b-airs or whatever, making reads), but if Fox chooses to ban FD and then play super platform campy and safe and chip away at the ICs very slowly with shine until he's fighting a single climber the IC player should have kleenex to wipe all his tears away.
People assume that the ICs can use "mindgames" and "make reads or trick fox" into b-airs or stuff but don't consider that Fox can also think and trick the ICs while already playing from the advantageous position. I can't think of anything they have that would be able to fight that kind of play style.
When people see Chu beating mediocre Foxes playing like that it has more to do with Chu just being hella good and experienced compared to the Fox player. The Fox players on Chu's level that are just as comfortable vs the ICs as he is vs them really gay his character hard it seems

Try to look at it from a theory craft perspective for the Fox will make just as many correct reads/trick the IC just as many times as it will happen the other way around and not Chu outreading/outplaying the other.
(kinda covering 2 thoughts at once here... including the IC match up, end ramble)