Cause everyone already had learned how to "touch"-gui, but microsoft in typical arrogance, redesigned it from the bottom up, throwing all the learnings away, you either had from android or macos. And like introducing a third language, to do the same tasks you already can perform fluent in two other languages, it was just this constant stepping into the void of expectations. It came out 2012 https://en.wikipedia.org/wiki/Metro_(design_language) and was thus 9 years to late (1 iphone) and 5 years to late (1 android). It was moment were microsoft dediced to go uphill, that journey developers usually have to face, when dragging users away from windows (aka the universal gui). I mean, the normal user learns windows in school.

You only make that sort of learning effort on rare ocassions. And you dont make it just because your vendor locks you out of a previoulsy perfectly working for you ("You learned to know it blind") device.