That -def/-acc toggle also has a lengthy animation time and can often be skipped using in a battle. More so if they are simply blowing through content. Of Time's 9 powers, 3 are actual single target, so your listing isn't as truthful as you are implying. The only aspect which isn't covered in some way from an AoE stand point is -regen. Two of the single target powers for Time have -regen and let's be honest, the harder targets are the ones you want -regen on. Minions are cannon fodder. Two Ill/time controllers can use Temporal Selection on each other. Dual Chocking Cloud is useful, but Ill isn't in melee as much and doesn't have much to take advantage of with AoE damage as compared to Fire. Yes, it's useful. My guess is Distortion Field/Time Stop mixed in with Blind/Flash more than covers what's needed to be held.
Note, we are vastly arguing over semantics when it comes to god tier controllers. 😃