That's a good thing, because if you find a bug, it will be fixed for everybody, not just for your one-off init script.
Generally I agree with this at a broad level. But, there is still the problem of: I need this running now. To do that, I need to compile and run a custom systemd, and hope that my patch gets accepted upstream, and that in a few months my distro finally adopts it and puts it in the standard package.
Generally speaking I really like systemd and am excited to get some time to update my installed stuff to use it, but the above is a real concern.
We have SysV shim layers for that though. We had them in Upstart, and we have them for SystemD. Boiled down, it can still run shell scripts that look like SysV scripts, and will be able to do so indefinitely because that's basic functionality.
At the worst case though, this reduces systemd to a shim-launcher for SysV init, which is the situation you find yourself in now or when using Upstart, which tons of Ubuntu users already have been.
Generally I agree with this at a broad level. But, there is still the problem of: I need this running now. To do that, I need to compile and run a custom systemd, and hope that my patch gets accepted upstream, and that in a few months my distro finally adopts it and puts it in the standard package.
Generally speaking I really like systemd and am excited to get some time to update my installed stuff to use it, but the above is a real concern.