Just also an opinion:
“return nonsensical customs”
I am assuming that you are living in a country where the AM/PM is not the default format of presenting time. I was born, raised ,and currently in the Philippines and the 12-hour format is the default way of presenting time here. Aside from the train stations in the capital, I only commonly encounter 24-hour format on the military population because it has been their standards ever since, but to the majority of civilian population which I belong, this is highly confusing for us. The wall clocks being commonly sold here in our country are those rounded analog clocks with 12 numbers only, and so people commonly choose to “still” communicate the time through the AM/PM format (it is still quite rare at least for me to encounter digital clocks with 24-hour format, but this is not to say that those are completely unavailable here). So for me, I wouldn’t consciously readjust my perception of time because that has not been the standard way or presenting time to everyone here in our country.
“Who wants to live with the situation that …”
We didn’t necessarily want nor choose this kind of time-format in our country. It rather was just the standard way of communicating time. If I talk to my students or to basically anyone here about the time of 15:00 instead of 3:00 PM, I guarantee and assure that most of them (not all) will be scratching their heads or will have a difficulty comprehending what 15:00 is based on our perception of time.
I understand that this is just your opinion, and so I also wanted to offer my unsolicited opinion on your opinion, and so here is my lengthy answers. At least now I know from the other comment that this request can be filed under RFE.
