Nope. You're comparing them to someone who can literally through infinite amount of spells as long as they have mana. As Kennen, you can throw skillshots (which if blocked is useless) to apply Mark of Storms in order to use your W or use your ultimate which is useless the second there's more than 1 champion (roll the dice on which champion gets most damage). I just had a game with another AP Kennen who thought he was God in disguise and he got smushed so utterly completely because he didn't get fed.
EDIT: Also Ryze and Morganna's AP ratios are AP ratios on DoTs. If they were as high as Kennen, they'd shred everything. Anivia is a straight line skill shot that has to be activated (unlike Morgs), but it's still to prefer from Shuriken because this ability can go through units.
I'm not just saying this out of my ass, you're welcome to go test yourself. I almost guarantee you (many factors in games these days) that you will do better as AS.
EDIT: Also Ryze and Morganna's AP ratios are AP ratios on DoTs. If they were as high as Kennen, they'd shred everything. Anivia is a straight line skill shot that has to be activated (unlike Morgs), but it's still to prefer from Shuriken because this ability can go through units.
I'm not just saying this out of my ass, you're welcome to go test yourself. I almost guarantee you (many factors in games these days) that you will do better as AS.
[SIGPIC][/SIGPIC]