Is there any reason why SailfishOS couldn't be built on top of, say, Fedora, just like Linux Mint is built on top of Ubuntu?
The current repository state is a nightmare, with everything as old as the current CentOS release.
There's one thing most of people out there are missing, I guess. It's a really, really big problem that we have absolutely no app compatibility between Nemo and Sailfish. I mean, if you want your application work on both Nemo and Sailfish, you need to maintain two trees of your QML sources. That's a big maintenance burden. The lack of abstraction layer allowing to target both these platforms has a disastrous effect - there are virtually no Nemo applications, which means that those, who would sacrifice the eye-candy for a fully open source stack, well, can't. Even though the platforms are so pretty similar.