Gen Urobuchi has stated unequivocally that he had nothing to do with the ending of Aldnoah Zero. Washed his hands of it. So done. Once you see it, it’s easy enough to see why: divisive, to the point where it overshadows the rest of the series that, when all’s said and done, is entertaining but shallow.
It treads in familiar footsteps with its concept: mankind divided, the Earth threatened, a war fomented. A force with vastly superior technology attacks an unprepared populace, oh the humanity. This isn’t anything that you haven’t already seen before in numerous other mecha shows and, depending on the breadth of your experience with that genre, done better.