Why can't Teemo's W give speed when Nunu's ball is so broken?

Riot isn't fair to Teemo.

Here we have, yet another champion, that gets a stun, movespeed, and zoning all from one ability. Riot claims that Teemo cannot be buffed because he is a lane bully. Teemo has never been as toxic to the game as Nunu, and needs some movespeed to remain viable and true to his role.

Will the nerf fest finally end? Will Teemo get his rework? Why is it that champions like Nunu are allowed to remain so strong, yet if Teemo gets the slightest buff, the community is up in arms?