I thought there were others in addition to Slackware, but that pretty much all the distros are jumping ship shows the naysayers don't have enough political oomph.
Those that has adopted systemd are either precursors for commercial distros, said commercial distros, or based of same.
The really early adopters seems to have been offshots of Fedora. And i do wonder if Debian was a holdout until systemd started sprouting containerization features, and Canonical (Ubuntu) was feeling the heat.
