Almost all the Ratings I receive on my games are phrased like public reviews, clearly meant to be seen by others. This is a shame, because most of these people probably wanted to be kind, and didn't realize that leaving a comment would be more helpful. Therefore, I suggest three different solutions:

1. Be more explicit in the review description and state that it will not be visible by anyone checking out the game's page, and that it is basically a private message. It currently only states "Reviews are shared with developers and your followers", which doesn't make this point clear enough. In my opinion, this option would be the easiest to implement, but probably also the least effective, since some people just won't read the small text to begin with.
2. Make all reviews public by default, giving them a separate section in addition to the comment section. (However, just like with comments, developers should be able to disable this if they want to.)
3. Publish chosen reviews as comments. If a developer specifically likes a review, he should be able to make it show up in the list of comments, just like it was probably supposed to.

In case of 2 and 3, if the reviewer's privacy is a concern, maybe developers have to await the reviewer's approval before it becomes public.

Would love to know what people think of this.

I generally agree with you that reviews in general should be public. But while the way itch.io handles reviews is certainly unusual, to say the least, I didn’t feel like they made a big secret out of it. When you rate/review a game, right between rating and text there’s an info text that reads:

Your review

Share what you liked or disliked about this project. Our community rules apply here. Reviews are shared with developers and your followers.

So I think their kind words were actually meant primarily for you. :) Awww…

If this ever got changed, it would have to be an opt-in kind of change. I feel like people would riot if they signed their for your eyes only review with their real name, their email address, or included other private information that they didn’t want to go public. (Right now there’s an option under Privacy that enables users to hide their reviews from their followers.)