Let's talk about Critical Hits
Critical hits (or strikes, whichever) are usually an essential stat for an AD carry. It provides a 2x multiplier to your attack damage at a set chance. This chance can come from
blades somehow, and also as a free stat for broken-ass champions who need reworks.

For some champions, critical hits work thematically:
Ashe's arrows slow her enemy, so landing a critical blow is
teed afterward. I think that's why her auto attacks deal bonus damage on frosted targets.
However, critical hits are strangely implemented into
's rockets, allowing her to deal 2x damage in an AOE. A precise hit on a crucial part of an opponent are not in the nature of a rocket, especially on multiple enemies at the same time. It's also not in the nature of Jinx:
http://i.ytimg.com/vi/V0-vcxZD3j8/hqdefault.jpg bitch is crazy, not calculating.