I wasn’t suggesting mandatory I was responding to someone else’s comment on them being mandatory and that we would regret it if they were.
I like the idea of tying the ratings to reviews but I also think there should be something to encourage purchasers to rate and review their purchase, even if it is something as simple as an email like: “Hey, thanks for purchasing [Insert product name]. Don’t forget to rate your purchase click here blah blah blah” that could be made into an automated email that is sent a few days after the purchase. Or some mechanism in the launcher that would promote leaving a review and rating after purchase…like on eBay when you make a purchase you get reminders to leave feedback on your purchase.