in my opinion.... the parts they would cast molds for in the MOTUC for MAttel are rather simple 1 -3 pieces which as kup has mentioned I suspect as well has several molds pre made already since it is simple, where as if you look at a transformer leg, there could be a lot of pieces involved. Not to mention for bigger pieces (Voyager above) there would be joint pieces and wotnot inside the legs piece alone which would all have several molds, if just one mold of this several molds to make a leg degrades then the rest would be affected, and upkeep I guess would be costly if you have to remold a small piece all the time since each mold might be degrading at different times..... or his could all be just BS from Hasbro.