I wonder if Samsung is holding that one close just in case Google irks them with Android. Right now, it probably makes more sense monetarily for Samsung to stay with Android.
Google and Apple both rely on ecosystems to attract and retain users, and Samsung doesn't have a competitive (or compelling) ecosystem. <end north american centric summary of problem>
I don't know if Samsung has the same problem in other markets, but I know that Firefox Marketplace does/did.