Why does Ahri's Q give her movement speed?

Haven't you ever seen anime? Fox girls always getting raped so she needs to run fast to get away from them.

http://na.leagueoflegends.com/en/news/game-updates/patch/patch-52-notes

Fantastic Ms. Ahri's success as a support-killing, pick-making assassin has always been tied very closely with Deathfire Grasp. With the item gone, however, it became obvious that Ahri's unique role in the game was losing focus, so we set out with the goal of moving her back to her original vision as an ultra-mobile kite mage. Technical improvements and updates to Fox-Fire and Spirit Rush should make her feel smoother to play, while Orb of Deception's new mobility effect allows her to both outwit opponents in close duels or remain elusive as she repositions in a fight

Why are you the 435,348,913 to person to post this?

She's an elusive hard to catch mobile mage. that's why.

They removed death fire grasp which was core in her, removed damage amp from charm, lowered the range of her w and r projectiles, and lowered her passive sustain.

I think for all that you can deal with a half second speed boost.

They nerfed her damage really hard, and they wanted to compensate her without letting her instantly blow up people if she lands one charm without being fed. Unfortunately for riot, the movespeed boost is actually way stronger than the extra damage because being able to kite and throw several rotations of spells is way stronger than just having more burst but dying after you run out of ult charges. Also the movespeed eliminated her only weakness in lane of being gankable without her ult.