Well, most people like to have some semblance of normalcy to their lives. Time zones accomplish this by making everyone’s daytime correspond with the actual hours that the sun is shining in the sky. Without time zones to keep your daytime hours in sync with the sunshine hours would require your day to start at different hours depending on where you lived. If you happened to live where the sun rose at midnight that would be your start for the day. And could you imagine the fight over who gets to have the time coincide exactly with what we are all normally used to? We can’t even agree on controlling greenhouse emissions. This dispute would probably end our known civilization or at the least cause all our nocturnal people to move at once.