And then it magically happens that you sleep as much as you need. Being a long time supporter of naps I find myself not doing them at all.
Of course this applies only if you have flexible hours to work, don't have appointments, etc.
My life has improved after I started getting up extremely early (0400) four or so years ago. And that doesn't happen without an alarm clock.
My point is not to say that you are wrong but that we might be better off trying different solution for ourselves instead of believing in authorities here or elsewhere.
(I'm not saying you shouldn't listen to normal advice like getting good sleep etc, but don't think that getting up at 0400 will solve your problems because eitland says so and don't think that waking up naturally will solve all your problems. Instead try one, then the other if the first didn't work.)
Too many people don't know how much sleep their body would want if unconstrained by alarms. Once you know, you can get decent results of manipulating when you get that sleep with alarms. But if you don't know it's very easy to be near constantly sleep deprived.
It's extraordinarily useful for planning when I am not getting much sleep. If I must be somewhere at X o'clock, and I can't get a full night's sleep for some reason, I make sure I am going to sleep so that my alarm starts going off when I am at around 3.5 hours of sleep or so. I've missed too many meetings and flights trying to get 5 or 6 hours of sleep. And if I've just pulled an all-nighter and need to be somewhere in 2 hours, I don't go to sleep unless I have someone who can literally kick me awake at the appropriate time, 'cuz nothing else is going to get it done.
[0] Yes, I've read enough about sleep to know most of the details behind such sleep rhythms.
[1] Well, having children does change that a bit, but a beep-beep-beep isn't going to get the job done.
That said, I get by on little sleep and can be productive in the evenings when I know I have more time available if I get on a roll. Wake up at 5am and parents inevitably have kids up and distracting them from 6:30. Work at 9pm, and you can carry on until 3am or longer without distraction.
Although personally, I don't think one needs flexible working hours to achieve it. Once I got my habits and home lighting right, my sleep cycle very naturally became: sleep at +/- 10:30, wake at +/- 6:30. That only works if I stay out of sleep debt, of course. But that's entirely worth it; I didn't realize how much sleep debt was harming my mental clarity until I experienced a long stretch of sleeping enough every night.