From my experience, the bigger the company/team working on it, the more blind you will be for obvious misguided dev directions. You might think "oh well, this particular idea might not be the best", then you visit tons of standups, meetings about the progress of things, dailies with artists, devs, designers hyping their new shit that's really cool, you see QA and collegues playing the game all the time and having a blast - mostly because they kinda have to - and tend to see all the good things, the cool ideas being worked on, the little details you really like, the positive outlooks from product and project, the motivational words from c-layer when they do their usual spiel, stuff like that.
You get sucked into the general "hype" of doing a cool thing with a big team, and suddenly your doubts turn into a tiny nitpick that's probably not even worth mentioning.
Then come the playtesters, who have been handpicked, and likely mostly report the positives, then there's the next super cool cutscene you get to see, and so on and so forth.
If you compare that to like a team of five people worrying about their future every day, it's a completely different mindset (and a much, much higher ignorance when it comes to negatives).
Again, just from my personal experience, but that's generally what I think happens with these AAA flops easily.
