Why do you think 15 minutes prior to 15 Minutes prior exists to such a level that virtually the whole military has accepted it as standard?

We've all heard it, regardless of branch or unit we have all heard "Be here 15 minutes prior". So much so that people even stop saying it just expect you to be there 15 minutes before any scheduled formation or event.

The reason why is obvious, your leadership wants to ensure you're there.

How did 15 minutes prior to 15 minutes prior to 15 minutes prior become a thing that most of us can laugh about because we've experienced it?

Has anyone experienced or witnessed units try and punish Soldiers for not being 15 minutes prior but still showing up on time?

To tell my own story I have seen a unit try and punish its Soldier for showing up for example at 0652 instead of 0645 with a report time of 0700 only to be denied by JAG because no official order was given and a general expectation can't be substituted with an order.

I have also seen discussed that the military expectation of "15 Minutes Prior" may be a cause for Civilian employers incorrectly telling their employees that they are "required" to be at work 15 minutes early without being paid.

So what are your thoughts on this? Is it all the fault of some Joe's who were too late too often and ruined it for us all or is it just an inherent culture of I can't be wrong for higher so be here earlier than early?