A lot of people prefer to stick to the old sysV-like initscripts setup that most distros used before systemd (and is still an option on some, though with extra steps like adding orphan-sysvinit-scripts in Debian and manually removing the relevant systemd parts as IIRC there isn't a standard install-with-sysvinit option without installing a much older release and upgrading via a couple of dist-upgrade cycles (which keeps your old setup as much as is practical)). It works for them, has less bloat that they might not need, can be easier to debug, and they know it well, …, though isn't as well-supported any more with some packages that provide services just defining systemd jobs and you have to work out an alternative yourself. Debian even includes other init systems (like the one from Gentoo) - there is more than systemd out there if you want to try something different. Some people would still prefer upstart, which Ubuntu used for some time before moving to systemd.

I'd prefer to keep the older sysvinit init scripts, with all logs just going to text files rather than the systemd journal, but not so much that I make the effort to “fight” to keep things running that way on new installations. A lot of stuff still works the old way anyway (journal logs being mirrored to files in /var/log, init-like scripts in /etc/init.d calling systemd parts to mimic what the script on its own would have done previously so you can still `/etc/init.d/apache reload` or such).