Getting as little sleep as we do is 'un natural'. I'd argue that, including a nocturnal wandering break of some kind (as I recall hearing used to be normal prior to the widespread use of electricity) around 10 hours of darkness (on average) and 'rest at night' would be what we evolved as being setup for. To instead push the boundaries to midnight or later (as I tend to want to do my self) and then to be required to get up before even 8AM is really not leaving enough time for good rest.

It doesn't help that the area I'm in is closer to the 49th parallel than the 45th and also has easterly mountains; thus making natural sunrise artificially later. It's no wonder Seattle has such a caffeine addiction.