I disagree with you completely. Well, not completely, since the damage you are talking about is actually true, but I definitively do not believe he needs a gank. You said it yourself, his weakness is that he's melee, he's unable to get in there and deal this "outrageous" damage he has and, if he closes the gap onto the enemy, guess what? he also burnt his escape. Master Yi hits like a truck, that's true, but he's not a Jarvan, a Xin, a Vi that can close the gap and soak damage while delivering his, if he gap closes and gets caught by a single CC, he will most likely be blown up to bits.
I believe he's at an "alright" spot right now. He's still viable as a niche pick, when the enemy fails to build a team with CC that can stop him (kind of like Kassadin and some other champs that can snowball), but it hardly deserves a nerf (MAYBE, and this is a big MAYBE) adjust the numbers on his Alpha Strike, but other than that, being Melee, Glass Cannon and give absolutely not a single one way of CCing the opponent (be it a slow, a stun, a silence, SOMETHING) makes me think he shouldn't be nerfed.
J4 has a knock up, Xin has a slow, Vayne has a stun/push, almost every comparison will be like this for Yi.
What I think the problem you have when talking about Yi's abilities and comparing them to other champions is the same mistake I read on the GD QQ's thread by Bronze players, no difference. You cannot simply compare similar abilities without looking at their kit and the champion itself.
If Vayne gets caught, for example, she can go invis and either escape that situation (avoiding point and click stuns) or re-engage after getting better positioning, getting to actually use her tools. Yi, not so much, a point and click CC will keep him in place long enough to burst him and even if it doesn't, vision of him enables other abilities to be casted unlike Vayne. With Corki, you've got the leap and well, the fact that he has range.