If you end up with a giant ball of hidden complexity, that's a strong indication that you're dealing with that complexity at the wrong level.

Both PulseAudio and systemd seem to have the "throw everything out, start from a beautiful abstract interface and work down" mentality, which is a recipe for the mess that they've ended up as. Sometimes the best thing to do is pass the ugly complexity one layer up - which is, I think, one of the things that Unix does mostly right.