I realize that I could probably find out "bad things about HAL" via internet searching, but it would be more interesting to see the author's take on the issues in the context of the article.
Nonetheless, "the udev debacle" refers to systemd merging udev into its codebase, along with tying it to systemd's shared files, the recent "debug" parameter fiasco and the rather blunt statement by Lennart concerning migrating the transport to kdbus: http://lists.freedesktop.org/archives/systemd-devel/2014-May...
PulseAudio (originally PolypAudio) is a networked sound server most often used in Linux systems coming with a variety of centralized features (see here: http://www.freedesktop.org/wiki/Software/PulseAudio/About/), which proved to be highly controversial initially and less so to this day. People realized it was buggy and unstable, and different factors were blamed: poor integration, sloppy ALSA drivers, or PulseAudio itself. The most common narrative these days is "PulseAudio was bad because Ubuntu rushed it", but I haven't studied things in enough detail to pinpoint exact reasons.
As for HALd, it did solve problems at the time, but I'll quote the Ubuntu wiki: https://wiki.ubuntu.com/Halsectomy
So that really worried me when I found out Arch linux was switching to systemd! Thankfully it's all been ok as far as I can tell. Had to learn a few new commands and that's about it. Maybe it's different for the people actually configuring daemons, but as far as the end user goes, I haven't noticed any problems.
> The fallacies that systemd opponents make have been pointed out so many times that it’s not worth giving a comprehensive overview.
Great, now I have homework to do before I can read your article. I guess I'm just not in the target audience for this article because I haven't been following the debate from the start.