If I watch a trailer for a movie I can't review the movie based on my thoughts on the trailer, but I can decide not to watch the movie if I don't like the trailer. Same applies here, they're clearly shitty so nobody should go there, but you can't rate them on the food/service because you never tried those.

And plenty of man created things have hard and fast rules, it's not exclusive to reviews, otherwise we'd be walking around naked in forests. Man made creations have rules so that they work as intended, that's why you can't simply walk to a bank and ask them for a hundred million even though money is a man made creation (just one of many examples).