While it may be true that ADC's deal too much dmg, but they are kind of suppose to. People forgot that they are Attack Damage Carry. But the drawback in that role is that you'd be really squishy, opening the window to being one shot which is where the Enchanter support problem comes in. In addition I find it really (insert appropriate word) that everyone says ADC's are "broken" when it doesn't cover all of the marksman champions but only a certain number of individuals.
Strong:

Okay:

Weak:

But then again with that, people forgot that no other roles are suppose to carry. Mid laners serve to be as secondary damage and executioners, top laners to deal and tank damage, tanks to provide CC and absorb most of the damage, and supports to obviously protect and start the engage.
But I guess times change, and how things are now anyway. Where everyone wants to carry no matter what role they play, which is fair enough I suppose.
##For those who might get the wrong idea, i'm not suggesting that other roles aren't suppose to get kills but that Marksman were originally suppose to be able to carry through their constant DPS. It's the Critical Strike or the overall itemization that made Marksman strong as they are in the first place, not really the champions themselves.