The problem isn't blender, maybe the people that made those renders there aren't that talent in that software.
Lust&Passion, A Wife and Mother, hired an animator to work in blender and the new animations are pretty good. Those were made in blender and the characters appearance didn't change, like it happened here in the previews. I think that Oppai-man switched to blender for the same reason, it's better for the animations. The difference is that L&P continued to use Daz for everything else and blender just for the animations. Besides, it seems that they did different processes, it seems that Oppaiman's team did the characters again from scratch, while L&P transferred them from Daz to Blender.