It's cool, but it's not what you'd normally understand "Linux" to be. It implements the Linux kernel syscalls, so it supports most of glibc and some of the GNU userland, but misses a lot of the stuff that makes Linux, well, Linux. You can't use iptables. No namespaces AKA containers. When you get to userland, your session is just a bash login shell. There's no DBus, no systemd, no X11, no clipboard. You have to do some fairly ugly hacking to share an ssh-agent between two consoles. And so on and on and on. It's cool for some things, but not good enough for some other things, and I don't see it growing support for those in the future either.