Talk:Sivir/@comment-26274286-20180511124242/@comment-26808509-20180514152009

It once scaled with AP only for balancing reasons. Q was only good in early game back then with a much higher base damage (around 400 with both instances hit) and no reduced damage per enemy hit.

They later introduced the reducing damage, lowered the base damage and added the AD ratio to let it scale with her item build. No one wants an damage-only ability that doesn't scale with anything you build and Sivir's kit simply doesn't synergize with hybrid items or on-hits. Similar AP scaling abilites on AD champs at least either have an additional AD scaling or they serve an additional purpose outside of dealing damage.

Examples here are Miss Fortunes E (slow field), Yasuo's E (dash), Lucian's W (movementspeed buff) or Ashe's Ult (Stun). Having them scale with AD would mean to lower the scalings they have on other abilites or their AA's and as Krufix said, these scalings make use of random buffs like Baron.

I didn't include Kog'Maw here, because he doesn't follow pure AD-build paths and likes hybrid/on-hit items wich indeed synergize with his AP scaling. Outside of that they of course have additional effects aswell (Q the resistance shred and passive attackspeed and E slow).