I am quite a good touch typists and that makes it so difficult for me, to switch layouts. Once your muscle memory is hard wired, you cannot arbitrarily change things. Last time I had to type on English layouts, it reduced my ability to touch-type greatly.
Right, that's what I did. I stuck with the German layout, as this allows me to use my native language too. But his means, certain characters, like brackets, are more difficult to type and thus the assumption, that everyone is using an (US) English keyboard is a wrong one.
But in a general sense, I fully agree to your statement. Learning to touch type was an extremely valuable skill to acquire and I can only recommend it to everyone.