User blog comment:TheTobarMethod/Do AP's Need A QSS Upgrade?/@comment-60764-20130904015231/@comment-5556439-20130909115619

They have CC for the same reason APC's like Nidalee dont.

Its synergous with their kits and how they use the kit. Tanks are the only type of champions that have consistently high levels of CC due to their nature to go in and be a meatshield. If theyre going to be in the front then they might as well have the ability to keep enemies there since no one else can and needs the "resource bandwidth" to deal damage or support.