A combination of factors. Price, obviously, but there's also the issue of slipping quality control and, personally, most of these things look like absolute nightmares to transform. I don't mind a transformation scheme that's challenging, but watching someone transform these things rapidly turns into a mess of parts moving and I have no idea what the hell's going on anymore come step 35. It just seems like the devotion to accuracy does more harm than good most of the time, turning the figure into a needlessly fiddly mess. On that note, if I can be perfectly honest, I really don't care for slavish screen accuracy and can deal with some creative liberties here and there. I still think the old Classics 2.0 Hound is a great figure and representation of the character, for instance.