yes, but those review aren't really public, aren't they? They're only visible to the developer or if you follow the reviewer. The only way to have public written reviews (also visible to the outside public) is to write a comment. Which is a separate action from the review prompt. That seems inefficient. Couldn't the rating system+the comment section be grouped together? Couldn't the system prompt me to rate & comment when I try a game? Isn't it better marketing for the game if its page is full of comments? A game might have been reviewed 20 times but if its page has no comment I'm strongly inclined to think no one cares about it. Don't creators always say every little comment helps, even if it just say "good"?
And for those people worried they might get intentionally hateful reviews if they're public, the comment section could always be disabled.
Is the current review system really benefiting creators and customers? Since it's not public, what happens if you follow people that never review games?
(some personal glossary just so we're clear
rating: a purely numerical point system, in our case represented by stars
review: text whose purpose is informing a potential customer of the value of an item. By this definition, one-word reviews also count)