The problem with PA is that (it appears like) there aren't really any simple errors. For most software, you have a bunch of common problems that you can find on Stackoverflow easily with a reliable solution.
Pulse, on the other hand, while working fine on 99% of systems, usually fails catastrophically in creative ways on the remaining 1% and it's really hard to even understand what the problem is. (And of course, these 1% will shape public opinion. A large portion of the 99% is not even aware they're using Pulse.)
Yeah, I've certainly had to learn a few tricks to debug audio issues on my Linux systems. Last one was a crash when disconnecting Bluetooth headphones, traced to PulseAudio unloading its Bluetooth plugin from code within the plugin. You don't get a backtrace if the crash is from returning into code that doesn't exist anymore. I still haven't figured out why this didn't cause crashes on all systems.
Factors which will have majorly affected people's PulseAudio experience over the years include audio hardware, what software they use with it, system uptime, local RF interference, use of suspend/resume, which patches their distro backported, and the exact stack and heap layout of the process on their system.
Two nines isn't very many nines. I've had problems with PA 100% of the time. Must be me, right? The only PA solution I know is purging it from my system.
Pulse, on the other hand, while working fine on 99% of systems, usually fails catastrophically in creative ways on the remaining 1% and it's really hard to even understand what the problem is. (And of course, these 1% will shape public opinion. A large portion of the 99% is not even aware they're using Pulse.)