There's no reaason why an Android app can't be as good or better than an iPhone app. I think that there are three primary issues at play:
1) Apps are created by developers who have to choose how much of their resources to spend on each OS. Apple had a big head start on installed base of phones so many developers have prioritized on developing for iPhone, but then may have chosen to do a quick port to Android, which they may or may not improve over time.
2) Android phones have much more variance in the hardware capabilities (some of which are inferior to the worst iPhone, and some of which are superior to the best iPhone) so some Android apps may be written to the lowest common demoninator.
3) I've heard some people say that there are Android apps that don't look as good on the iPhone, so I think that the OP's sample size was probably not big enough to make a fair comparison.
Android is now beating iPhone badly in market share. As Android's market share begins to dominate, more and more developers will develop first for Android, and then port to iPhone.
Android Is Destroying Everyone, Especially RIM -- iPhone Dead In Water