I know most Poser users are "end users" but still I think it is clear that much/most Poser popularity derives mainly from expert user hacks like mat poses and injection poses for instance. What is cool about Poser is that historically it was very platform independent because of the text-file based content... the fact that you can modify content using a simple text editor. <<<

But try to take that "really cool and hackable" format into another 3D app, and that's where you start to see the challenges and limitations. A lot of the "breakage" could occur in making Poser more compatible in handshaking with the industry standards available in the  "big boy" apps. And that is where you start to see the points that Gareee addressed ... at what point does a developer draw the line between supporting the old, and moving on toward the new?