I mean dude, he's not talking to people with medical issues. I don't think anyone would besmirch you due to a medical condition. I think he's talking about people without sleeping conditions, just Gaussian distributed recruits that want to get in. The services will ask and test you on these clear issues like people that can't drink a gallon of water in under a minute or folks blind in one eye. Also, being a night owl is not a medical condition, what your brief comment describes is obviously a medical condition that would disqualify your from the services. You life is not in anyway easy because of it, as far as I can tell from this comment. It's not a big deal. However, if what the researchers say is true about the widespread 'night owl' prevalence in the population, then it is obviously not something that can't be corrected with a very loud and buff drill sergeant, as many many cohorts of incoming boot camps across the world for centuries have shown.