Worse still, some of the code in that daemon exists pretty much solely to replace functionality in that one shell script: the negated ConditionPathExists seems

Worse still, some of the code in that daemon exists pretty much solely to replace functionality in that one shell script: the negated ConditionPathExists seems to be used only by sshd.service, with the non-negated version being used only to decide whether to launch getty. We've essentially replaced complexity in a shell script with complexity in an always-running process written in C.