User blog comment:Tjmachado/Let's Talk... Support/@comment-4888212-20131121060226/@comment-1330314-20131121093327

Actually, the supports that are being reworked for Patch 3.14 are going to have their damage-related AP scalings significantly nerfed, along with their bases. CC for days is all well and good, but you're going to need burst damage to make any use of it, which the updated core supports won't have. ADCs aren't geared towards burst damage, and adding a mage or an assassin would mean having 4 squishy champions (since your supports would be going full AP) on the same team, which is invariably a bad idea.

Lulu's gotten the best deal in terms of AP scalings, since Pix is now a full mini-, and Taric could be a viable top against AD champs, but Janna, Sona and Soraka now get outscaled even harder by mages in terms of damage. You're better off having someone with less utility and more burst, otherwise you'd get diminishing returns. Additionally, if you pit a support against a damage-oriented the support will lose in a one-to-one fight, and by extension would lose their lane.