I find this article bizarre. I wake up at 5AM so that I can juggle personal goals - fitness, hobbies, etc with my workday which goes from ~10-5. I typically can work out in the morning, beat my coworkers to work (start work at 7:30, they get in at 10), wrap whatever I had to for the day before my 10AM meeting, spend time during working hours exercising more, playing piano, or flying drones, then do a bit more work, cook AND STILL be in bed by 9:30PM to support my sleep.
Yes, many early risers who are "cultish" are total dorks that are sleep-depriving themselves and evangelize their wakeup time to appear "elite", but if I miss sleep I know it immediately - I feel mentally drunk all day and get mood swings, make simple mistakes, forget things, and oversimplify tasks. As such, I try to be in bed by 9/9:30 to get ~7 hours of sleep which still irritates my tension headaches, increases my workday stress and comes with a whole slew of compromises.
Regardless, I wouldn't trade my rising early lifestyle for the alternative - oversleeping (11->8), getting into work at 10, feeling tired all day, getting 30% as much done, no hobbies, no exercise... no thank you.