The Play sore app does even require a Google Plus account when you just want to leave a rating. Ratings are 100% anonymous as they don't show up in the reviews and are global (where as reviews a language specific). This just doesn't make sense to me.

Mobile apps that require a e.g. facebook account as their only sign up have up to 50% drop offs because people don't want to sign in with a service like Facebook.

I strongly believe that ratings and reviews are a core function of a app store eco system. Links to profile pages don't give me as a person who wants to download the app a real benefit. Google did a really nice job with their NLP to highlight reviews that had more depth in the store overview.