I go out to restaurants to enjoy and have fun, I don't project-manage what everyone should order in advance. The experience is more enjoyable if things are spontaneous depending on how the meal has gone so far. A case in point is desserts and there is a reason the traditional way is to order desserts after the meal: It let you order based on how you feel after you have eaten!
My wife used to work in food service, and I was surprised when she told me that she preferred it when people asked for the check upfront, because that table suddenly wasn't taking up a concurrent process in her head.
This essay was supposed to be more about politeness than efficiency, but maybe I didn't express that very well :)
In addition to the points you made:
- It's a waste of time deciphering social cues just to judge whether a table is ready for the check.
- If the restaurant is reaching closing time, I cannot close out the cash register until I have every check. The sooner I close out the system, the sooner I can let core waitstaff go home. Keeping staff around for one or two late tables is a waste of resources. Better to have the checks up-front and close on-time.
That takes more time, than ordering all at once. But, if I order everything at once, it get prepared nad served quite fast after another, while the first dish still isn't empty.
So that's a Problem! You get urged to swallow your meals as fast as possible. It's good for the restaurant, but not for me and my eating habits.
As I pay for that, I see that as not my problem, but rather a problem of other people.
The time savings last aren't that big. And customers who sit long spend more on drinks..