That's not how it works.

Yes, RT scores are binary, but that's not the same as saying that "rotten" means 1/10 and "fresh" means 10/10.

Yeah, that’s not the same. That sounds worse to me, so the question stands, how is it better?

Please note that I'm talking about critics' ratings: RT has them and IMDB doesn't.

So it's better for me, as I value known critics more than random people.