I am worried even more that people people may well have used upstart for a number of years and still think they are using sysv, because upstart could grok the scripts without change.

But then i am sitting here using a distro that boot by way of a couple of flat files. Frankly i kinda like it, but then i grew up fiddling with autoexec.bat...

> because upstart could grok the scripts without change

I don't believe that's the case. The "service" command (which is part of the sysvinit-utils package, not Upstart) invokes either Upstart or SysV init as necessary, but Upstart itself has no awareness of the SysV init world. You couldn't have an Upstart service depend on a SysV init one, list SysV service status with Upstart, or enable a SysV service through Upstart.

In case you're curious, the wrapping on the systemd side is more comprehensive. SysV scripts appear as units, and systemd parsed the semi-standard metadata at the top of most SysV init files to determine when the service should start if enabled (translating from the traditional run levels). As units, the SysV init scripts are possible to enable/disable, start/stop, and list using the standard systemd commands. They can also participate in dependency graphs alongside systemd units.