If this actually takes off it could be a good idea. Creating a common base for libhybris derived projects to share some of the workload seems like a sensible route.

As far as using Android kernels etc. I would like to avoid it where possible as well. Unfortunately due to the lack of open source drivers for some componenets you sometimes have little choice. If you try to get a working version of Maemo on something like a Samsung Galaxy or Sony Xperia, I think Android drivers are going to be the only way to do it.

I had been intending on getting a RPi 3 to work on an experimental version of hildon that would run on a stock distro/kernel. Unfortunately, due to some compatibility issues with my 3T, I've gone out and got a Moto G5, eating away at some funds. Trying to get a Maemo-like system running on that would probably require libhybris for the time being.