So why isn't there thunderbolt in iPhones/iPads?

There isn't even an accessory that Apple offers so I can use it.

It has been a while since the introduction of Thunderbolt, with the iPad 3 and the 4S (I think) being launched without any option to use Thunderbolt to transfer data.

Is there any chance it will be included in the iPhone 5?

I know it's kind of unnecessary, and that Apple is trying to go all cordless, but I still think it should be an option as an accessory, or even an adaptor of some sorts.