What the hell did he ever do to piss off this many people, anyway?
The controversies listed on Wikipedia https://en.wikipedia.org/wiki/Lennart_Poettering#Controversies don't seem all that bad.
I guess people get totalitarian vibes from his comments about making Linux more streamlined and opinionated? https://linuxfr.org/nodes/86687/comments/1249943 There are some pretty hard limits on how far that can be pushed, though, seeing as how Linux is used in everything from mainframes to microcontrollers. Flexibility isn't optional.