Why doesn't Graves Quickdraw have a "lookahead"

Lookahead is when a dash abiliy "looks ahead" to see if there is space beyond terrain, in case the 400/475 unit dash falls into terrain. It's what makes flashing over walls possible, and dashing over terrain.

Now, most dashes, (Lucian, Nidalee Pounce, Vi's Q, Tryndamere's Spinning slash, Sejuani's Q, Gragas's body slam) Has a look ahead, which makes the "wall jump" ganks possible.

But why doesn't Graves have the same luxury as some of the newer (and even some older) champs have?

If anything, this is prime example of mobility creep on ADCs.