There's also Alpine Linux. And in Debian you can switch to sysvinit or upstart.
If you're really anti-systemd maybe consider FreeBSD, PC-BSD, or OpenBSD.
I expect this to go the way of the dodo by the release of the next major version.
Only reason it works right now is that Canonical had interest in maintaining a shim between the systemd APIs and upstart. As both Debian and Ubuntu now defaults to systemd, i expect said shim to rot on the vine.
The major thing though is that systemd is not just a init.
At present is it init, login, logging, xinetd, cron, firewall, networking, and the list keeps growing virtually daily.
Meaning that providing an option means providing effectively two distros.
Most everyone who hates on systemd has this problem; you could blame systemd. Or you could realize you have a problem
Frankly the reason systemd even gets attention is because the likes of Gnome needs a part of it, logind, to handle logins/sessions, and that it basically absorbed udev (after udev had existed as a independent project for a decade).