What you're really describing is bad UI design. It's not a fault with the interaction method at all. Your whole argument that "keys are well documented" can fall down if a developer doesn't bother their hole to document their keys, or to follow a standard keyboard pattern.
I completely agree it's bad UI design, but it's also become the standard. Some modern "standard" did away with buttons that look like the buttons we spent 20 years learning the look of, scroll bars that look like the scroll bars we spent 20 years learning the look of, hotkeys with underlined letters that we spent 20 years looking for and learning to speed our interaction with frequently-used programs.
It's absolutely bad UI design, but I think it's become the rule rather than the exception. It's just "prettier", according to some jerk who never used a hotkey in his life.
