I think part of the resistance you'd meet to labeling piano keys is that you're highly unlikely to be able to play well if you depend on looking at the keys, as it slows you down too much to be able to play anything but the slowest pieces, whereas you can write well (though arguably not type well) on a keyboard while still looking at the keys.

As a teaching tool, labeling can work for both, but as a crutch for people who are less than proficient, labeling does not work well for someone trying to play the piano. There's a greater need for getting to a certain level of proficiency if you wish to play the piano than if you wish to use a keyboard.