Developers want a market (consumers), consumers want content (by developers). A classic chicken-egg feedback loop.
Easier to develop apps is just one point that can ease the feedback loop, but its not sufficient...nor is it shockingly necessary (just look at Apple).
Disclosure: MSFT employee, just sharing what I've learned about platforms (and what many probably already know).
My point was that barriers don't matter much when you have a healthy market to receive your app. So while we might work on lowering barriers, its all for not if the store is a ghost town. This is very humbling to us PL/tools researchers.
What keeps you working on Apple's platform is the popularity of the app store, if you couldn't get customers; you would leave in a heart beat for a platform that had a healthier market. Look at all the people who learned Objective C...not because it was the best language, but because it was a technical barrier that was necessary to overcome to access a healthy market (and technical barriers are much easier to overcome than market barriers!).
Easier to develop apps is just one point that can ease the feedback loop, but its not sufficient...nor is it shockingly necessary (just look at Apple).
Disclosure: MSFT employee, just sharing what I've learned about platforms (and what many probably already know).