[masklinn]

> whereas Linux distro splinters have (largely) remained compatible due to licensing and cultural differences.

Seems to me this had nothing to do with licensing or culture, but rather that if you wanted your distribution you'd use the upstream kernel and build your own userland with blackjack and hookers and whatever direction you were interested in, so there's some measure of strong relatedness in the kernel everyone shares. You might add a few modules or patches, but few people bother (or need) to fork the kernel itself.

Since BSDs are systems, if you want to go your own way you fork the entire system (that's literally the genesis of both OpenBSD and Dragonfly).