"Let's get non-musicians making music! We'll just give them a nice MIDI keyboard instead of that hard-to-use violin"

Sure, this will skip over some tricky bits of getting started with programming, just as a MIDI keyboard can make it easier to make violin sounds without having to learn all that pesky fingering.

However, as with playing the violin, those bits aren't really the hard part to learn; the easiest to use keyboard in the world won't make you a composer and flow based programming is not going to make you a programmer.