The complaint by the anti-systemd crowd is that the systemd crowd is actively promoting things becoming dependent on systemd. It's not that they can't maintain a systemd free distro, it's just that nobody wants to spend all of their time undoing the work of the village idiot. You must have missed the articles about organizing a Debian fork. Or the whole uselessd thing. If systemd would just keep their fingers out of everyone else's pie, nobody would much care what they do or don't do.
I have fixed the btrfs/systemd problem. I gave systemd the boot and now the VM just works.
It is actually kinda funny to me after hearing all the systemd can do anything! systemd is great, all hail systemd cheerleading not to mention the excessive delight of some of the fans that people might have problems avoiding it and then a really simple problem comes up and literally the whole community is stumped. Not just a little stumped, they actually have no idea how to handle the situation even in principle. Meanwhile, going back to sysvinit fixed it right up.