If he has done nothing for the community at all, that's still better than having worked on dbus or systemd. Bad progress is not progress, and people making bad progress can't hide behind it as a shield against criticism.
People like you are the toxic part of the community. If you don't like dbus or systemd then either come up with a better alternative or use whatever else you prefer. But attacking someone on a personal level because you don't like their stuff is just incredible toxic and annoying. Especially if you have nothing to show for yourself.
No one is showing up to your house and reformatting your computers. If you like the old stuff, keep using the old stuff. If you don't like the new stuff, don't upgrade to it.