I think some times that we've designed our presets for the night owl, and not everyone is a night owl, so we are working on it.
But the challenge is -- we'd like to make using the software more automatic, not less!
The "bedtime" mode is designed to allow your body to produce melatonin on its natural rhythm -- this happens >10 hours before you wake up, for most people (and maybe even earlier in the winter).
The melatonin rhythm is totally separate from a "cue" to go to bed, which is a separate and important thing (it's sort of why we did the backwards alarm clock). And as you say some people only spend 7 hours in bed and are quite happy about it. As it is, those notifications are sort of a prototype, and if people want us to we can make those cues a lot more customizable, and there could be a screen change too. Because I do agree that cue is pretty important.
I prototyped the notifications with a recurring calendar that was super-annoying (but I liked it better), and it would pop up and say "Get ready for bed now!" because I could do that when it was my schedule, but we had to make it more "objective" for this feature, so we weren't being totally rude for people who had to stay up late for some reason.
We have some ideas about how to let people say, "This is too early" or "This is too late" and have the software adapt. I think if we exposed an extra 5 parameters most people would find it too complicated. But we will probably have some more advanced parameters in a future version.