The old UNIX principle:

Software tools should have a clearly defined scope. Software tools should stay in their lane. If a software tool is highly privileged or highly complex, pay particular attention to (1) and (2).

This design principle has lasted the ages because it limits the scope of any particular bug, and it makes it possible to swap out problematic tools in a modular way.

SystemD deviates from that in quite consequential ways.

Then there's its historical management culture.

User: "D00d, when I create a user account called 0day, SystemD comes along and gives it root. Is this expected behaviour?"

Lennart: "WontFix"