"Poettering is known for having controversial technical and architectural positions regarding the Linux ecosystem"
The "people hate him because he makes new stuff" narrative is just more ego-protecting cope. Many developers of other new systems are widely respected and appreciated because their stuff works and they stay humble. Wireguard and Pipewire devs don't get hate poured on them in HN discussions because their shit works, solves problems people have, and because they know how to deal with people.
It does become a problem when you have a system service developer who thinks the universe revolves around him, and nobody else matters, and people sending him bug-reports are annoyances that should be ignored rather than acknowledged and fixed. At that point, it's a problem.