[coldtea]

>But iterating over the characters is a very useful feature. It's used in all string algorithms that I can remember in the time it takes to write this comment.

And you still do that with atomic strings -- you just either add a helper method like charAt(i) that gives you access to each character (or, rather, each rune), or you have some way to turn a string of length N into a list of N strings of length one.