because we were all over in FCP7 land, and all the developers were over there with us. Then a lot of them plunked down for X based on the assumption that the FCPX market was going to be huge, but, that said, quite a lot of developers have announced PPro compatibility recently. Also x has some pretty serious architectural shortcomings in how plug-in GUIs can operate onscreen and in the inspector.
some interesting stuff has started to appear for PPRo - I've posted it before but, this dude for instance.
http://vimeo.com/user1590967/videos http://www.ogallchoir.net promo producer/editor.grading/motion graphics