I have a Grav/Time Controller that would disagree with you.
She has no damage procs in her powers and, granted doesn't defeat x8 mobs as fast as a Blaster, she goes through the fights in near perfect safety.
But then, that's what 4 holds (2 of them AoE) and a Singularity can do for you.
I also had an Illusion/FF Controller that would disagree with you as well.
He was able to tank multiple bosses on teams of 8 back on live before IOs were even a thing.
My Illusion/Storm Controller is a force to be reckoned with. (With no damage procs and half the powers using SOs)
In short, Controllers are fine the way they are.
Just don't expect them to play like Blasters.
Same goes for, pretty much, all of the support classes.