Sven Hartge:
... except when its one-size-fits-all approach does not work, of course. Example:systemd happily runs "legacy" LSB init scripts
* https://unix.stackexchange.com/questions/386846/This is the problem with even Mewburn rc scripts (as I can attest from personal experience of writing replacements for an entire Mewburn rc system) let alone with van Smoorenburg rc scripts (which are far messier than Mewburn rc ones). One size does not fit all. One really is not going to ever get a backwards-compatibility mechanism that copes with all such scripts in the general case "happily".