Morning was when I was forced to wake up to go to school, it was when I’d have water thrown at me if I slept in on the weekends, it was when I’d have to get up early to help my father with the boat.
At night time, I was left alone. And night time still brings me comfort. I suspect morning people had more positive morning-related experiences than I did during childhood.
Keep in mind that your circadian clock changes with different life stages. Teenagers have been shown to have circadian rhythms that run a few hours later than that of adults.
One example: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2820578/
I don't drink any coffee and have a lifestyle very similar to OP's, and usually can't fall asleep before 2am. It strikes me as improbable that people with similar lifestyles would have different sleeping habits. However, some of us may have developed these habits for the very reasons you mention; I for one had a terrible time at school.
It's pretty tragic, imo, and it's one of the biggest reasons I want opening hours to shift later.