simple to answer..

they are not making a figure that has to be all things to all ppl (see poser figures +morph demands, where a figure is almost expected to be everything from a baby to an old crone and everything inbetween) and..thats about it really.

if you think about it, we put demands on the figures we use that defy logic. where it would be better to use a purpose built figure to be the old woman, (which would give far better results), we try to make a generic figure into that old woman... and expect that figure to also be the man, six armed thing over there, that tree and oh, can I find a morph to make it into a young perfect woman?

they can make a figure that just is.