I think this decrease of lucidity when you sleep shorter isn't necessarily the case for everyone.. for me at least I actually have lucid dreams more often when I sleep less, like this week I have been sleeping 4 hours per night because I've had tons of work and I had around 3 or 4 lucid dreams in 7 days, without actually thinking about it.

And as for motivation, does it happen to you guys too that once you're having an LD you can't remember a single thing you were planning to do so you just end up flying or making out with someone?