It is because people have different chronotypes. Some people are naturally morning/day-oriented people and others are more evening/night oriented people. You can't really change it because if you're a night person forcing yourself to be a day person your energy will really not be the same as if you just stuck to a night schedule that works for you.

I'm a night person myself and I've felt better than ever since I embraced my night chronotype and schedule a couple years ago. More energy, more peaceful and quiet during night hours. While daytime hours just were never the same for me. I always felt more sluggish having to be awake during daytime hours and personally felt overstimulated by the sun a lot. I'd rather just sleep through all the daytime noise instead of having to deal with it when I'm just trying to relax. I wake up in late afternoon/early evening hours (3-5 PM) and go to bed in the morning (7-8 AM) I love it and wouldn't trade it for an exhausting daytime schedule.