I was a fan of upstart. It was simple, it knew how to perform the task it did it, it didn't try to be everything plus the kitchen sink, it worked well and it didn't get its tendrils in everything like systemd does (something that concerns me as it increases the attack surface).
It was a technically superior solution murdered by politics.
What's worse was all of the people who were going "why are you moaning? what's wrong? systemd is still an improvement on sysvinit!" as if being better than a bunch of bash scripts held together with bits of sticky tape and string was all the qualification needed to be PID 1.
And yes, people do erroneously paint it as only a choice between van Smoorenburg init+rc and systemd, as if they were the only two possibilities, when in fact in the Debian Hoo-Hah (for one) it was effectively a choice between systemd, upstart, and OpenRC, nearly all parties agreeing at one point in the proceedings that van Smoorenburg init+rc was last choice, either before or after "further discussion".
The criticisms levied at upstart there are more about lack of features, not really about overall approach. It's easier to add features than it is to fix a deficient design.
Moreover, I'm not really so sure a couple of those features even belong in an init system.
Debian's decision effectively doomed upstart and led to an init system monoculture. The practical upshot is that no competition for systemd means no pressure to improve. Even for systemd it was a bad decision.
Actually it was about overall approach. Read M. Allberry's further discussions in that bug with Colin Watson, Steve Langasek, and others. Josh Triplett critiques it as well. Cameron Norman's discussion with Nikolaus Rath is also relevant. There were actually quite a lot of technical discussions about the fundamentals of the various architectures. Ian Jackson's and others' discussions about readiness protocols is worth reading, for example.
One cannot truly portray this as either "politics" or only about lack of features.
It was a technically superior solution murdered by politics.
What's worse was all of the people who were going "why are you moaning? what's wrong? systemd is still an improvement on sysvinit!" as if being better than a bunch of bash scripts held together with bits of sticky tape and string was all the qualification needed to be PID 1.