The problem is they've irrevocably assigned themselves that responsibility. Google does no curation of the Android Store, therefore they have no responsibility

The problem is they've irrevocably assigned themselves that responsibility. Google does no curation of the Android Store, therefore they have no responsibility for its contents. Apple, by putting every app through an approval process, has taken on complete responsibility for the App Store's contents. That being said, despite the occasional screwup (and having been the recipient of an unfair app rejection myself), I think the App Store is a better place overall because of the curation.