On the topic of Microsoft cancelling this game because they knew it was going to be sub-par, I would imagine they considered it but there was just no way that was going to happen. Not only would it have been more bad press over another cancelled game, they'd already made SUCH a big deal over this game in particular. They'd pinned their entire "Power of the Cloud" gambit on this title. Cutting the cord would have meant a ton of explaining. Besides, they still need games for their service, even if they're not very good.
Also, this "the critics just don't get it" theme a few people are running with seems kind of silly. I'm sure the critics get it, they're just not particularly crazy about it. Personally, after watching gameplay video, this looks like the kind of game I'd get bored with in under an hour. It's like the superpowers game-play of Saints Row 4 but without all the other awesome stuff that made that game a blast to play. If a game like that is a Happy Meal then a game like this would simply be an order of fires and a cup of water--for the same price.
I can imagine why someone might like this game. However, I can very easily see why more people would find it boring or underwhelming. When a game simply gives you the same thing, over and over, with no real personality or substance beyond more of the exact same "mindless fun", I think a low score is justified. Honestly, if someone gave it to me for free on PC, I probably wouldn't even download it.