Rotten Tomatoes isn't actually automated like that. Critics mark their reviews as positive or negative.

So in both of your examples, 9/10 people said "Yeah, I liked this" so you have a 9/10 chance of liking it.

It's worse in your opinion because you're trying to figure out how good something is and that's not what it's for. It's there to tell you how likely you are to enjoy something and it's much better for that.

RT only tells you what percentage of critics gave a positive review, not how good something is. This is like having your height measured and complaining about how that number didn't tell you your weight.

I have no idea what it is you're trying to say.

What? How?