These are excellent points. But what if a musician is hired to compose a song that is to be played on a brand new instrument? Would the musician not want the in

These are excellent points. But what if a musician is hired to compose a song that is to be played on a brand new instrument? Would the musician not want the instrument to be playable rudimentarily very quickly, so he can begin to demonstrate where he is going with the song, so as to get early feedback? While this is a tortured analogy (as a musician, I want no feedback until I'm done). I believe that wanting tools that optimize for the long-term, coupled with needing early feedback is precisely why many use certain technologies for demos, then build in other technologies. The faster the demo can be built the better. The earlier you get feedback on the UI the better. The earlier you show a demo, the sooner you find out what the user really needs as compared to what you've been told (and the sooner the user finds out what they don't need, despite what they thought).