Ashe vs. Master Yi: Doesn't this seem completely and utterly unfair?

Ashe can't slow Master Yi, and thus can't even crit him when he's using his ultimate. This more-or-less cuts her damage in half against him later in the game. You'd think Riot would've separated the slow and the Frost Shot "check to crit" parts, but nope, they're the same. As such, since Yi almost never will fight with Highlander down, and his ultimate's cooldown isn't even that long, Ashe will never have a window of opportunity in which she can safely engage Yi.

Her only hope is ECA, but Yi can easily dodge that with Alpha Strike, negating Ashe's only defense. Now, you'll probably just say "Ashe shouldn't stray from her teammates", but realistically that's not always possible, or Yi could avoid being peeled off her. And last, Ashe can't even build defense against him because Randuin's doesn't work on ADCs, and Yi gets true damage from Wuju Style anyways.

Players should always have some way of dealing with an opponent one way or another, but in the Ashe vs. Yi case, there is NO solution. Ashe just automatically loses and the onus is entirely on another player to save Ashe.

Doesn't that feel wrong? I thought 100% hard-counters weren't really allowed.