As you mentioned in IRC, this is probably just documented behavior. From reboot(8):
When called with --force or when in runlevel 0 or 6, this tool invokes the reboot(2) system call itself (with REBOOTCOMMAND argument passed) and directly reboots the system. Otherwise this simply invokes the shutdown(8) tool with the appropriate arguments without passing REBOOT‐ COMMAND argument. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1349566 Title: systemd-logind triggered poweroffs ignore upstart services Status in “systemd” package in Ubuntu: Incomplete Bug description: systemd-logind has a facility to detect non-ACPI power-off events (e.g. a power button push) and initiate a system shutdown. This facility works in Ubuntu - it manages to shutdown the sysvinit services, but upstart services do not appear to be cleanly shutdown. Among other things, it means that local filesystems don't get properly unmounted. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1349566/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp