There are three main reasons. First, quite a few diaosi were shocked by the ending. In fact, as a princess, if there is no trip to the earth, the ending will be with Huang Mao, and with this trip to the earth, it will only be with Huang Mao. Although the yellow-haired boy has no scenes, his identity is beyond doubt. He is probably the childhood friend of the princess who really knows the roots and is suitable for the family. Second, some people expect too much from the script. Although this work is a tribute to Gundam, there are many shadows of Gundam, but it is not Gundam after all, so the fighting rhythm like Altman is not particularly out of line. Third, many people don't regard this work as a prequel to the series. In fact, it can be seen from the name aldnoah zero that this should only be the zero part of the aldnoah series of stories, that is, the prequel part. If you look at the end of the work from the perspective of prequel, it's not too bad.