Maybe at some point but we don’t have this right now. Reviews currently aren’t publicly browsable for games, they are only visible by followers of the accounts that create the reviews, and by the game developers. We’d like to make some updates to how the reviews system works before opening things up more.
Viewing post in Web API for Ratings
There is already a shitty way to get all reviews/ratings from Itch. I will not explain how (so I don't get banned by angry devs,) but I will hint that https://itch.io/feed?filter=ratings is a feed of all ratings, and doesn't require you to be logged it. Have fun.
P.S. Anyone who can scrape reviews with the hint was going to figure this out anyway.
P.P.S. Guys, either restrict reviews to be "friends only" (or even "author only") or make a normal API - this is silly.