Hi Mike,
I'm pretty new to the field of true 3d software myself (I use OnecncXP for 3 axis milling) but I am coming to appreciate quite strongly the benefits of using solid models, even for 2d type jobs, expecially since my software is able to create whatever type of path is needed, whether it be 2d or whatever. This eliminates having to redraw parts (error prone) and also eliminates the dangers of rapid gouging. The proofing tools are exceptional as well, so you can simulate the nc code very precisely to be assured that whatever nc code you have created is proper.
Sure, you can "fool around" with 2d CAD and create toolpaths, but as you suggest, that is not the modern way to work. Perhaps your machinists are "afraid" to use the high class software that your shop is licenced for? I have no idea how machinist friendly those programs are to work with. Could this be the source of the resistance to "make the switch" to full 3d?
As a small shop owner, head programmer and chief of the cnc department (I am the cnc department
), I can vouch for the user friendliness of the software I use, and I feel it represents an intuitive CADCAM solution that your machinists would be able to use to comfortably handle a lot of your programming (up to 3 axis anyways) with a minimal learning curve.