Google has a much lower set of standards than Apple. When I worked at ClearChannel, our apps got into the Android store on the first try, where Apple kept asking for revisions. They said our streaming video bitrate was too high, and it would eat users data and battery life. They even made us retool the app so that the RSS news feed sent a diff instead of the whole feed to save a few KB. It was annoying, but in the end it made a better product. Google lets anything into the store, and it shows. If they raise the bar now, however, they'd still need to prune the crap that's already there.

EDIT: A good first step would be to do a basic review of permissions. I have seen tip calculators that ask for location, SD card, read contacts, and more. This is clearly not related to the core app functionality.

I had the opposite experience. I heard about all the great games on the iPhone, so I downloaded a bunch of 5-star games. However, I was shocked to find that almost all of them were spammy and hardly let you play without making an in-game purchase. To me, spammy games which basically require in-game purchases do not merit a 5-star review. A free game on Android that is only superficially free would not receive a 5-star review.

Yes. as a casual user its almost impossible to find useful not spying apps there. Its basically full of spyware.

Google apps has made it OK for developers to make money on what on windows is malware and requires anti malware software for.