replacing integral parts of a system is always a bit of a dilemma. If we replace it only after all the other software/drivers that interface with it is known to work well with it then nobody will bother doing all that compatbility work since they can say "Nobody uses it yet, so why should I bother?" -- and hence the change can never take place.
If we replace it before everything works perfectly well with it, then folks will complain: "Oh my god, it doesn't work with my software/drivers, you suck!" -- like you just did (though in more polite words).
Hence regardless which way we do it we will do it the wrong way. Biting the bullet and doing the change is however still the better, the only path to improvement. With the limited amount of manpower we have pushing things out knowing that there is some software/drivers that don't work well with it is our only option -- especially if the software in question is unfixable by us since it is closed source.
Hence, if we'd do as you wish and not make the distributions adopt PulseAudio right now we can forget about fixing audio on Linux entirely and it will stagnate forever.
As mentioned by J5 this was the same story with D-Bus, HAL, with udev, and other stuff.
And again, folks may claim that PulseAudio is very buggy. While it certainly has bugs, like every software has, most of the issues reported are not things we can or should fix/work-around in PulseAudio, but that are in other layers of the system. In ALSA, in the drivers, in the client applications. However only PA makes them become visible since it depends on a lot more functionality to work properly than any other program before. And quite frankly we use a lot of stuff exactly nobody has used before and that of course was broken due that (in ALSA as one example).
Having said all this. Just pointing to other folks to blame doesn't really solve the problem. I did a lot of testing on different sound chips, making sure PulseAudio works fine on them. Of course it's a limited testing set (six cards right now to be exact, a seventh model currently being sent to me by my employer, Red Hat.). The list of cards that are currently known to be problematic are listed in our Wiki.
I am not saying that the points you make are rubbish. However, please see the big picture before getting vocal about it.