Personally I think this has a lot to do with Daz Studio being free. People have this tendency to think that "If it's free, it's probably crap". If I look at my own freebies, the poser stuff gets two and a half times more views and downloads over the same period of time than the DS stuff. That's probably about the number of times Poser gets downloaded from a torrent site for every download DS gets :-)
I've used the trial version I had of Poser8 a total of three times, before it expired, I don't feel like buying it, or even downloading it from a torrent site. I find the DS interface much more intuitive, everything is more structured whereas I find the Poser interface kind of daunting. Also, saving a material preset in DS is a breeze, in Poser it's a nightmare!
I also find it easier to create things for DS, the file hierarchy is a lot more logical than Poser's, where everything has to be in a certain folder for it to work.
I'm sticking with DS. Like you already said, just about everything that's available for Poser can be used in DS, so it's like having the best of both worlds, in some way.
Peace,
Tony