There are so many variables involved when it comes to making movies, from the very first word of the script to the last name in the credits, but the most important for audiences is what happens on the screen, and a lot of that rests in the hands of the actors themselves.
Miscasting has the potential to sink an entire movie, and has done so on countless occasions in the past, because if the paying customers aren't buying it then you've already lost the battle. In some cases a strong ensemble can elevate poor material to somewhere far beyond what it deserves, but other times even a roster of A-list stars can't save something terrible from sinking.
Whether they've misjudged the material or simply signed on for a paycheck and decided to completely phone it in, an ill-judged performance can have a massive effect on the quality of a movie. And when there's a cast jam-packed with famous faces all failing to deliver, then nine times out of ten the final product ends up being doomed.
I don't do social media, so like or follow me in person but please maintain a safe distance or the authorities will be notified. Don't snap me though, I'll probably break. I was once labelled a misogynist on this very site in a twenty paragraph-long rant for daring to speak ill of the Twilight franchise. I stand by what I said, it's crap.