Touch typing isn't "designed" for anything, it's not "designed" at all really. It's the idiom/phrase we use to describe typing without looking at the keyboard.

And yes, it's extremely useful for developers of software. Not all developers use an IDE by the way, and even if they did, autocomplete is not same as knowing how to type properly.

I find OPs consternation a little bit odd though. When I realized I was still hunt-and-peck typing at a point where it was a little bit embarrassing as well as being a hindrance to my daily activities, I just stopped looking at the keyboard. Problem solved in about two weeks.