They can't even if they wanted to. The script is liable to change half way after they signed the contract and then the whole plot of the film can change radically on the editing room floor long after they've stopped filming. Actors have no say in what finished product comes out of their work.
Because they made "the deal" to get famous in the first place.
They are owned.
Most actors are super dumb. They just read the lines and collect the paycheck, and give no thought to any of it.
They can't even if they wanted to. The script is liable to change half way after they signed the contract and then the whole plot of the film can change radically on the editing room floor long after they've stopped filming. Actors have no say in what finished product comes out of their work.