This is my reason why I hate them: https://lwn.net/Articles/676831/ and specifically this: https://lwn.net/Articles/676938/

All the discussions from the Docker team regarding SystemD feel like they want to push Docker Swarm and see SystemD as a threat to their business model. It would not supprise me if they downtalk Lennart Poetterin on a personal level.

Also to this day if we want to setup complex test scenarios we need the --privileged flag to run Docker in Docker.