Does that not go for AP yi aswell? When Ap yi starts his heal and you cc him to cancel it does that not make it an instant death for ap yi too? Even if he doesn't start his heal ifyou stun him that's basically an instant death too.
"As hard cc = instant death"
That go's for basically ANY champion that doesn't stack hp and armour/resistance. you get hard cc on an ad carry? Dead. Hard cc on ap carry? Dead. That can go for anyone.
It doesn't take that long to kill someone on ad yi. Especially 1v1 o.o
You act like 1 Q on ap yi will instakill. Maybe that's the case for a FED ap yi. But the same can be said for a FED ad yi. A fed ad yi will do more damage than a fed ap yi.
Scenario 1 :
AP yi does his Q. Does significant damage but AA's don't do much and takes a while to kill enemy.
Scenario 2 :
AD yi does his Q, catching up to his enemy doing minor damage, but 2 hit's because of %crit and overall attack damage.
See where I'm getting at?
Also, I accidentally up voted your post when I wanted to quote it lol.
There's certain things you're not considering, and you disregard the importance of CC on Yi only. Yeah, CC works great on other champs too (Except Irelia, Fizz, Gangplank, Morgana's Black Shield, Sivir, Nocturne...Stop comparing him to other champs, he's not other champs) but CCing AP Yi is more difficult because of how you play him. AD Yi has to Alpha Strike to either engage you or dodge CC, while AP Yi doesn't stick around for the CC.