of course the problem IS that the top apps are listed by purchases, not by ratings. there are several apps in the top apps list that have bad ratings, but finding their competitor product is often difficult. apps are categorised very simply and simply thrown into a bucket.
remember, there are no refunds on app store purchases. the cheapest of competing apps are invariably the most visible.
"The fundamental principle of science, the definition almost, is this: the sole test of the validity of any idea is experiment." -- Richard P. Feynman