If she played Bloody Knuckles with Lee Sin; who would win?
Also-- there are some champions in the league that look like really bad news. Like, beyond punchable news. Xerath, the almost-god, Syndra, a transcedent mage, Zed, a ninja who unlocked some forbidden arts, Hecarim, an shadow centaur-thing, Karthus, a lich, and the new Thresh, an undead-soulstealer. Does she really think she can punch her way through these guys if they ever decided to give her trouble? I'm not sure even trying to punch half the people from the Shadow Isles would even do anything.
Or put it this way-- If Vi ever comes across a problem she can't punch to bits, how would she react? Especially if this problem was trying to kill her?