During the summertime when the kids were not in school I would get up at 6am and be out the door at 6:30 for an hour (~18ish mile) ride. I could get home, shower and be ready to work by 8. Now that school is back in and I have to get kids to school my 630-730 riding time is shot. To do any weekday riding I will have to be out the door between 5-530. My biggest complaint is not the time of day, but rather the fact that I will need to buy proper lighting (front and rear), plus add a reflective vest or something to my kit.

Lighting/visibility will be an expense that I make, especially with soccer/fall bball seasons starting up. My weekend ride time will soon be shot as well.

To help to answer your question, they do it because they enjoy it. As with anything, if you want it bad enough you will find a way to keep yourself motivated and engaged. Now whether or not early AM riding is your thing is up to you. But as others have stated, knocking out the miles early in the morning preserves my family time for the remainder of the day.