I’m with the zoomers on this one, honestly. If the workload is independent then there is no reason to demand what time the person gets started on that work load if it’s going to take the same amount of time. Yes, there are jobs where its time sensitive or assisting customers so obviously you need to be in place by a certain time, but that is not universal.

And it cuts both ways, if you consider it rude for a person to not show up by a mandated, arbitrary time, it’s equally rude to mandate a meeting or other function a person has to show up to that has nothing do with their job. I’ve been in the workforce nearly 20 years now, and frankly the number of meetings, events or functions I’ve been expected to go to that served no purpose other than to waste my damn time is way too high. The meeting could have been an email, the training might as well have been a check box, and if the party/event was so damn important why wasn’t I paid to attend?

TL;DR unless a person being late directly affects another person, then who cares? I’ll start caring about what a corporation thinks is rude when said corporations start giving a damn about my time and compensating properly for wasting it.