Pretty much stuff like "game is too repetitive," "it's too much like the previous game, not a real sequel," "story sucks," "you get too overpowered from mating with certain gods," "I don't like this one character," not really anything that should warrant a 1 star rating.
You picked out certain points out of longer reviews and I have yet to encounter any of those except the recurring criticism of the story. This strikes me as disingenuous.
The current top low ranking review complains about the focus on the Nueko character and that they preferred the self created main character of the original.
http://www.amazon.co.jp/review/RIJDZ6G3Y6M95/ref=cm_cr_pr_viewpnt#RIJDZ6G3Y6M95
Basically the character you play as isn't given much attention by the gods who seem to only care about Nueko. The game forces you to use Nueko in boss battles, taking away freedom in how to assign your party. She dies and needs to be reincarnated a lot. There are no scenes between her and the protagonist, making it hard to form sympathy for her.
And since they felt the game only cares about Nueko and not about the player character, giving them no opportunity to feel for the characters and story, other shortcomings which they put up with so far have become unbearable as well. They write that others already covered those so they don't go into detail.
Other reviews echo this criticism of being all about Nueko and the story being lacking.
Amazon is a terrible metric, since you don't need to actually buy the product to review it. On PSN, it has a 4.57 star rating with 210 reviews.
Lots of the 1 star reviews are buyers confirmed by Amazon. And they have high agreement counts as well, sometimes 3 digit.
You haven't read any of the reviews you just called silly. What you read is super short "summaries" by a poster here.
