I found #641206 after submitting this report. #641206 is for a similar request, but for init.d, before we had systemd in Debian. I'm not sure if the reason for tagging that as wontfix with init.d also applies to systemd.
- Bug#974665: `graceful-stop` by default? DJ Ramones
- Bug#974665: `graceful-stop` by default? DJ Ramones