I'd just like to chime in -- as someone who is really trying to learn the ropes in poser, I find it tremendously difficult to get any answers. There is no central place to find answers -- no comprehensive guide.

I can find 100 tutorials on how to conform hair to a figure, for example, in poser 4... but if I want to learn how to make conforming hair? Forget it -- I'm looking at days of poking around on the web. Eventually I end up asking here on the forums and if I stick with the thread and bump it a couple times, I might get at least most of my question answered.

I WANT to learn how to make the dynamics work. I don't need a beginner's tutorial the starts with "open the cloth room." I want a guide -- I want my questions about how a figure is going to act if I have a bunch of dynamics going and I have to render a series of complicated animations. What's the workflow going to be? What are the gotchas?

That's just one example of an answer I am never going to find with google. No good resources exist to get those kind of answers (or if they do, they aren't easy to find!).

So to answer your question: dynamic stuff isn't popular to make or buy because there isn't sufficient documentation about HOW to use them beyond the bonehead basics.