Im not saying bios are harder than corks, I'm saying learning multiple axis of rotation is hard. I feel like rotating on different axis should be worth just as much as spinning both ways, how many X games runs do you see with more than 2 different types of rotation in them? While you may see all 3-4 different directions, almost all of them are extremely similar rotations to eachother.
Thats why i like watching henriks slope runs, he's always doing something different, bios, flats, butters etc. Just my 2 cents.