It's practically common knowledge nowadays that the QWERTY keyboard layout that the majority of us use is pretty awkward and not nearly optimal for typing speed. The only reason it has succeeded is a combination of early luck and entrenchment.
Have you personally researched the basis for this "common knowledge?"
I stumbled across this excellent article discussing both the impact and basis for this myth. It's a really great reminder that just because something is "common knowledge" doesn't mean it's true.