Personally I hate to morph to too many character shapes. some body shapes just manage to distort the base mesh so badly that the textures stretcha dnllok like crap after. For many body shapes. Including GND2 and GND4 (which are completely custom morphs as far as I can tell) it;s just plain easier to make a custom fit outfit and in my opinion I can make it look better than a set that's made to fit plain V4 and then pushed and pulled into shape. That not to say it can;t be done! It's just that I find it more time consuming than the results warrent.

Also as far as the tools.. they cost as well. I use Carrara, Silo, Uvmapper pro and numerous smaller poser specific aps.I own WW2 and a few magnet sets but honestly the morphs they make aren;t very flattering, and require quite a bit of tweaking. Making the UVmaps alone cost me a lot of time (easier now with silo but still a good 3rd of the time.). Then there is the rigging.

Also and probably more the reason than anything else... I'd just rather move on and make something NEW rather than spend weeks more pushing and pulling something into a different shape. If I wanted to do that I probably  wouldn't be modeling but makeing character morphs instead! I add some morphs to clothing created to the gnereric base figures (V3, V4 etc.) simply to bow to the market, but I would much rather turn that part of the process over to someone else. I'd give free sets to someone that wanted to add morphs, LOL.

just chiming in
mike