Technically I appreciate much of the systemd design and implementation, but what repeatedly annoys me is when it 'takes over' - replaces - existing tooling and

Technically I appreciate much of the systemd design and implementation, but what repeatedly annoys me is when it 'takes over' - replaces - existing tooling and doesn't provide feature parity, resulting in regressions. The one that really annoyed me (and is still present) is when it replaced cryptsetup init scripts but did not implement support for root file-system key-files. For release-upgrades this will result in broken, unbootable, systems - it isn't difficult to imagine how this causes swearing and bad feeling! For new installs it means loss of required functionality, and lost time and productivity exploring and implementing work-arounds to counter the regression and return to the status quo. The reason for the lack of key-file support in systemd-cryptsetup? The purist idealism that key-file support patches will only be accepted if they use the Linux kernel's key-ring API (rather than replicate the existing cryptsetup init script behaviour).