I'm not sure how best to explain this. Stop comparing single damage to hitting several targets. You're making your case very badly.
I was responding to his Twin Strike post. I already did a comparison with Scorching Burst. Yes, I agree multi-target should be compared against multi-target. I've already done that in this thread.
The ranger is killing one guy. The controller is killing several guys. This is _good_ and _right_. In fact, if the controller weren't dealing more damage overall when he hits three different targets than a striker when he hits one that would be clear and present indication of a problem in the system.
The issue is that unlike the Wizard controller, this power gives the uber ability to target three targets as long as there are three targets, regardless of most other factors. It is similar in utility as Divine area effects that only target enemies. It's the reason that Clerics can be better damage dealers and better controllers than Wizards with area spells.
The possibility of targeting more than two foes with an At Will beyond the first round is ludicrously small for Wizards since a) the NPCs are not that cooperating, and b) targetting them with an area Encounter or Daily makes more sense in those scenarios where the caster can get 3, 4, or even more foes at once.
I have no problem with the area effect spell doing more damage than a Striker because of it's limited utility.
I have a problem with a 3 target At Will doing as much or more damage than the best Striker At Will in the game system because it can be used every single round when facing multiple foes. It has virtually no limited utility compared to an area effect that also targets allies. Pros without the Cons.
For example, the equally ludicrous counterexample to yours:
Twin Strike single target: ~25 per round
Hand of Radiance single target: ~7.5 per round
Clearly, Hand of Radiance is broken and needs to deal twice as much damage, at least, to compare. Hey, whattya know, that's wrong.
That's why all PCs get at least two At Will powers. So that the proper one can be used in the proper situation. It doesn't change how uber this At Will power is, just because there are a few limited situations where a different one is better.
The combination of increasing crit range and doing additional strong damage on a crit to the foe plus the targets around the foe just makes it that much worse to have a 3 target At Will power.