Efficiency in terms of not wasting people's time. The ability in business for people to complete tasks in-line with when they were expected allows for better scheduling.
I'm not suggesting that everything in business benefits from being regimented but that meeting expectations allows for others to plan their time effectively.
Time where people are waiting for others to do work which should have been completed can often be wasted.
>Efficiency in terms of not wasting people's time.
Then you must first consider the need to have the business or meeting in the first place.
In fact, people's time is only "wasted" because it has been made precious -- i.e. because it was stolen and/or sold. That's way more wasted time (they'll never get again) there, than in "wasting time" by not being punctual.
Societies studied by ethnologists had little care for punctuality. In fact the same was true for rural societies in Europe and the US as well (the US South was considered "lazy" and without a "sense of time" as well), and even urban life before the tyranny of the modern "always on" demands. For the upper classes, being fashionably late was a virtue.
Sure as I mentioned elsewhere I'm not arguing that meetings are an unalloyed good, what I am arguing is that where they are held, it is better that people are punctual, rather that non-punctual, and that there is improved efficiency relatively where participants are punctual.
I'm not suggesting that everything in business benefits from being regimented but that meeting expectations allows for others to plan their time effectively.
Time where people are waiting for others to do work which should have been completed can often be wasted.