I don't get it. They say that the default should be to kill everything that doesn't opt out, but that already has been the default. SIGHUP gets sent to all processes, and those processes can explicitly ignore SIGHUP. In the new scheme, SIGKILL gets sent to all processes, except if the process has requested not to be killed through systemd's API. A misbehaving program in the old scheme would still be misbehaving in the new scheme, so there is no added benefit.
The added "benefit" is that once more systemd gets to define behavior.
Systemd is not about building refinements on unix, it is about turning Linux into something like OSX or Android. a OS that use unix semantics only for bootstrapping convenience.
Effectively they are turning the Linux kernel into a convenient source of drivers, but beyond that could not care one bit about unix.
I really wish i could find the interview again where it mentions that Poettering in the past have advocated throwing away the chapters on unix programming from one of the seminal works on programming unix and Linux.
That's what I'm getting, but I'm trying to at least give systemd advocates the benefit of the doubt. When I have the time and energy, it can be a good use of time to poke at people with questions.
