As for testing--notice that when a lot of people here are reporting issues with systemd/pulseaudio, their reports are pretty much dismissed out of hand, or they're told "no, you've done something wrong".

For #2, a lot of times somebody with the right political position (say, Lennart at Redhat) or just the ability to shout louder and longer than anyone else will get something put in, regardless of technical advantage. Don't even try to claim otherwise.