Dieter Bohn, reporting for The Verge:

At the center of the Android app ecosystem is a fundamental problem that hasn't yet been solved: paid apps get better battery life but simply don't make much money in Google Play, while free-with-ads apps appear to be much more profitable but provide a much worse experience to the end user.
Bohn makes a good point here. This is the reason good developers don't build Android apps, but go to Apple's iOS instead. You see, it costs a lot to develop a nice app -- this is why many apps in the Android Marketplace (now Google Play) are either plagued with bugs or lack crucial functionality. If Google doesn't do something to fix this major problem, then Android's ecosystem will never get any better, but only worse.