Well, to be fair, Daz actually anounced the release of V4/M4 for Genesis since the very begining, their idea is to have a "Gene Pool" of figures, old and new, and allow them to use the new rig, plus any new content, so you could, e.g, have a V3 shape on Genesis, and use any new Genesis clothing, plus get rid of a lot of bending problems.

Where they went wrong, I believe, was in releasing V4 shape before any other new shape, because for custormers it might feel like just paying for V4 all over again, which esencially is. They should have release a lot of new content first, V5 shape even, and THEN release legacy figures like V1/2/3/4 as a Genesis shape.