What if there was a mtb (mini thunderbolt) to mtb charger for iDevices?

Not my world. I charge my iStuff either in the car or when they connect via USB3 to my rMBP.

It would most likely make those iDevices more expensive and make the cables more expensive.

it would be like hooking up a fire hose to fill a 6 ounce glass of water.
what's the point.

• USB is already out there, everywhere.
• it provides enough power
• if they made the jump to USB 3, there would be more speed than the internal storage on the iDevice can handle, and even if your computer only has USB2 (or, the horror, USB1) it would still work.
• did i mention USB is already everywhere, on almost every computer (if not every computer) that ships today.

Thunderbolt has it's place.
in much the same way that you wouldn't want to use a fire hose for your kitchen sink, you don't need thunderbolt for eveything.