i don't think you are clear that JACK and PA are attempting to solve different problems.

i didn't fully anticipate how different until i went to the linux plumbers conference last year. by far the most important user of linux audio facilities these days is neither the desktop nor the pro-audio/music creation communities. its mobile devices, phones in particular. when i say important, what i really mean is "where the money is".

the needs of the mobile device community for audio is so far away from what JACK is about, and much closer to what PulseAudio tries to do that its not suprising that the companies (like Intel, Nokia and Google) who are funding development of the audio systems that drive mobile devices are focusing their attention on the system that caters to their products' needs.

JACK is cool, but its latency and "performance" focused design is a liability on designs where the consumption  of CPU cycles, memory and above all consumption are primary considerations. Apple again did the right thing here by coming up with a design that works almost equally well for high latency and low latency applications, but even Apple has had to promote a different API for iPhone and iPad developers that looks more a traditional queing model than the callback-focused design of traditional CoreAudio (and JACK).

Saying that JACK is "better" than PulseAudio is like saying that more(1) is better than cat(1). Or that my Honda Fit (Jazz for europeans) is better than my neighbour's Ford F150 truck. They don't try to solve the same problems. They don't even really want to solve the same problems. And most importantly, AFAIK their developers don't want to solve the same problems.