I think Poettering deserved his fair share of the blame for the problems in Pulse Audio. However, a guy writes an over ambitious project, has a lot of problems, has problems with interfacing with users, etc, etc, etc. This is the internet! Pick a random project an Github and you'll probably find similar issues. The
real problem here was Red Hat -- and it was literally the same problem with systemd. They tied it so closely with the rest Gnome that you couldn't reasonably use Gnome without it. And since all of the distros were essentially riding on Red Hat's tail, everybody got strong armed into using this stuff before it was ready (to be fair, it was years and years and years before Pulse was stable at all).
I am not a fan of Poettering's code or his attitude, but people have treated him exceptionally badly. He's just doing his job. If these projects were allowed to compete for mind share fairly there would be no problem. If Red Hat had made sure that Gnome could work with alternatives then there would be no problem. Pulse audio would have died a rightful death. Systemd? I suspect that it would still have succeeded.