I have used a lot of Linux distros from Yggdrasil onwards via say Mandrake. My first kernel was 0.something. Back then we only had Miguel's method for init scripts. (I think). I use Debian, Redhat, Ubuntu, Arch, Gentoo, Centos and others at least these days. I now have only one initscript language to worry about.
gerdesj is specifically referring to the well-known problem that the helper utilities and functions for rc scripts varied wildly from operating system to operating system.
It's worth noting that the Debian people introduced another set of conventions recently, in 2014, with rc scripts in the Debian variant of the van Smoorenburg system now interpreted by a /lib/init/init-d-script command instead of a shell.
* http://jdebp.eu./FGA/system-5-rc-problems.html
Times have changed. My laptop that travels around a bit with funky VPN and proxy requirements is not the same beast as my desktop or server of years ago. Random bits of hardware get stuffed into it and pulled out with scant regard for common decency.
systemd is without doubt a bit odd in places (I'm a Brit and have experience of odd) but it provides a pretty decent approach to a PID 1 experience in the modern dynamic world.