Filmmaking is a collaborative effort. Even if one subscribes to the auteur theory, that the finished product is solely the director's credit, there are controlling interests involved at every step of production that compromise, alter or outright reject stories and ideas, shoehorn in concepts or worse.
A lot of it comes down to money, and this is never truer than the American blockbuster. Any major summer action film is going to have certain quotas they want to hit - beats within the script that feel familiar so audiences will get the most out of their already overpriced ticket.
And that's where the problems begin. One doesn't have to look far to find a time-filling, plotless set-piece simply there to keep the screenplay beating.
Other, more ambitious projects are just wrong-headed. Major opuses that have earnest intentions can easily go awry, particularly when the source material isn't worthy of high-art. Even some high-end directors can fall victim to this.
That said, there are inklings within some dreck that show potential. The ultimate product just decided to go the wrong direction.
Here are some scenes that suggested, at heart, withheld kernels of a better movie somewhere.