While I'm not a vendor, I see why they don't include the morphs: Time.

I've tried my hand at modeling and found I have less then zero talent for it. However, I have made items from primitives and learned a bit about the process. Every single morph that you make requires that you deform the mesh to the morphed position, then save it as an .obj file, then load it into the piece as a morph, name the dial, etc. If you count up the number of morphs possible in, say, a dress, it's easy to see why the vendors choose to go with only the few that THEY think will be most used. They don't count on people like me who think that EVERY Vicki character needs breast implants and NGM modification. (ROFLMAO)

The bottom line is, the more time they spend on an item, the more they will need to charge for it to turn a profit. 

I also suspect that most vendors know about Morcloth and it's relatives and have the "why bother" attitude, as they know it's possible for the user to modify the piece to suit their own needs.