FYI, you don't really need certain equipment to chart or playtest an instrument. You just have to be able to look at it autoplaying and tell if it's wrong.
Well, no, because you can still take liberties on Pro charting. Simple stuff like how far you move to play the next part can be missed because of technical 'accuracy', while in-game, it feels more difficult for new users(and let's face it, there's more learning Pro players than experienced).
To say nothing of the Harmonix employee providing other reasons.
Witticus: "GeeNef speaks to me like schizophrenia, his words touch me where my priest could reach."