Please don't be a sarcastic asshole. pstuart [Edit: not you] said you saw "posts" that showed it was unsustainable, and provided no citations at all. The fact is that there currently isn't a body of peer reviewed evidence to look at about the long term sustainability of polyphasic sleep.
But it doesn't take much evidence to refute an absolute claim like "polyphasic sleep is unsustainable". If someone is sleeping for 2 hours per night for a five months and says they feel energetic, that's damned compelling. That isn't "It really seemed to cure my headache!" It's "I am still functioning normally after 20 weeks with only 2 hours of sleep per night."
You also can't reasonably compare the priors of homeopathy and polyphasic sleep. If homeopathy worked, we'd have to toss out just about all of the theory behind physics and medicine and start over from scratch. Polyphasic sleep doesn't contradict current scientific knowledge.
I'm also not sure if the "sarcastic asshole" comment is called for. Not only is the stuff I said not sarcastic, insults of that nature are also clearly against the rules.
I am sorry that I came across as insulting. I interpreted your putting "citations" between quotation marks and then calling them impressive as sarcasm. I'm not sure how else to interpret it, but I will accept at face value your assurance that it was not intended that way.
I did not intend my statement as calling you an asshole. Rather, I perceived your comment as assholish. I assume that you are not an asshole, so I was requesting that you not act like one.
Your "citations" are impressive, but at the end of the day they are just anecdotal evidence.
We also have many accounts of people who claim homeopathy works. Should we believe them?