Asking why/why not to use systemd is covering very old territory here at HN and not the point of my earlier comment - I was riffing on someone using the term ''a bit dirty'' in regards to a Linux distro.
I understand the point of your comment, and that why/why not is mostly a philosophical/political/whatever question.
But really, the “I use both as needed” is the statement which pokes my interest. When do you need something else than systemd? What is the actual work which doesn't run with that particular init system?
I'm honestly unsure if you were just joking or if there's really something more to it.^^'
Another reading of that comment would be that they use Debian (with Systemd) when needed, and personally prefer Devuan for philosophical/personal reasons.