Knowing what most of the plug-in developer do for a "real" job, many of them have been very, very busy with there work leaving little time for additional development for the Carrara folks.

This is always a fine line to walk. To make it more worth the developers time, they need to earn more money. The plug-ins for Carrara are EXTREMELY low priced when compared to the plugs for other 3D software. Of course, when you charge more you loose clients. 

Additionally, because of the heritage of Carrara and it's price-point, a large portion of the Carrara user base are hobbyists that aren't willing to pay as much as pro studios. The Carrara market is really growing rapidly now though so who knows.

I'm just happy to have most of the plugs ported over to the Mac side now!