I agree -- recency is more important IMO. Particularly reflecting change in management, change in processes, etc.
For restaurants that aren't chains, processes may not be tried and tested -- first week jitters, hell, first month/quarter jitters should be accounted for.
There's a psychological and human aspect that some deem as positive that you are overlooking. While some shun away from the human experience, it's refreshing to head to an In-N-out burger and have well-paid smiling faces take your order and serve you delicious food.
Sure you could automate that kid, but while trying not to be sappy, that's another face you get to see during the day amidst a traditional day filled with computers, iPads, and now according to this -- machines making our food.
When I want to socialise with people, I'll go to a bar, my friend's house, a coffee shop, etc. If I want a burger, I want to get issued with that burger ASAP, without having to deal with someone who you may consider to be a nice person, but I may consider to be a douche-bag.
If that well-paid smiling person didn't have to work at the burger place, she might have something more interesting to talk about when we meet in a proper social environment.
I find that having a face to face interaction with another human being at least once a day makes you feel more human.
Sometimes I can go a few days to a week where me and my friends are all busy doing things, I buy all my stuff from the self checkout or via amazon and don't really interact with anyone.
Then when on friday night I go out to a busy party it feels like a shock.
For restaurants that aren't chains, processes may not be tried and tested -- first week jitters, hell, first month/quarter jitters should be accounted for.