User blog comment:Fistful of Force/Why I believe dedicated supports are better than AP supports/@comment-24022269-20131124230231

Scenario 1:

Annie stuns their carries while the rest of the team damages the other team hard enough to force them abandon baron, despite death on both sides. Or undedicated Annie just uses Zhonya and combos again for more stuns.

Soraka heals the tank but the tank gets cc'd and the carries get ran over hard.

Scenario 2:

Annie stuns Nid while the carry run like hell and heal from homeguard bonus and back while annie runs back to base herself and heal. Or the ADC just shoots Nid three times and get that 500 HP back via lifesteal (slight exaggeration).

Soraka heals but Nid throws another spear in the mean time so the support dies anyways.

Neither of the situations are situations where Soraka is much more likely to be superior to Annie, per se. Plus, it's been said but early game harass and stun is much more useful to get an early edge on their ADC than Soraka in certain matchups.