I think the first one is 95% of the explanation for the state of iTunes. iTunes was essentially done a long time ago, but it's rare to encounter software teams

I think the first one is 95% of the explanation for the state of iTunes. iTunes was essentially done a long time ago, but it's rare to encounter software teams that will go to their manager and say "our product is perfect. we shouldn't work on it anymore". And if you have a product that's done but you still need to work on it, what do you change? You change the parts where improvement is most subjective and hard to measure: like the UI.