> (You could of course have a scale of restaurant variety rather than quality, and in that case surely a PizzaHutTacoBell would rate higher than either a PizzaHut or a Taco Bell. But that's surely not the kind of rating we're talking about here—is it?)
You seem to be making a fairly strong argument and then confidently drawing a conclusion that is the opposite of the one the argument suggests. The value of food is determined at the most fundamental, objective level by what else you've eaten recently. If you are short on something, your perception of taste will change so that the nutrient you are short on tastes better. What's the argument for variety not being a part of food quality?
I was attempting to separate out the "variety" aspect, which as you say cannot be evaluated in isolation and thus makes no sense to print in a guide, by proposing long time scales. Would you really argue that nothing is left once you factor out variety?
> [Do you really think t]hat the whole idea of Michelin stars is entirely nonsense?
I think the perspective some other comments have taken, that there's more to food quality than whether you like it, is entirely nonsense. I don't think the concept of rating is nonsense; everyone likes some things more than other things. But I think your attempt to interpret restaurant ratings doesn't look very good.
> That food quality reduces entirely to variety?
No. But I'm happy to state that the union of Tim Horton's menu with McDonalds' is superior to either alone.
Well, it's too bad it doesn't suit your purposes. I hope you find an interpretation you like better!
> There's nothing about a 1-10 scale that implies that every visit to the restaurant will be equally pleasurable.
As for frequency, I think that might have more to do with variety and familiarity than quality. Surely, even if you agree that Tim Horton and McDonalds have equally terrible food and you hate it, you'd be more willing to be condemned to eat, each day at your choice that day of either of the two, than to be condemned to eat every day at just one of them, chosen today for all time. But that clearly doesn't mean that the union of Tim Horton and McDonalds has food that is less terrible than either of the two, which would be contradictory.
(You could of course have a scale of restaurant variety rather than quality, and in that case surely a PizzaHutTacoBell would rate higher than either a PizzaHut or a Taco Bell. But that's surely not the kind of rating we're talking about here—is it?)