> I'm also sure that a restaurant feels that recent reviews should be weighted heavily, almost exclusively, and that those two star reviews from last year should be ignored.

I agree 100% with that. It's very possible for a restaurant to get better or go downhill in a year.

If a restaurant has a rough opening but drastically improves after a few months, the early 1-star reviews can do some serious long-term damage even if they're a year old.