Three of Britain’s Oscar-nominated screenwriters say that an increasing tendency among film studio bosses and directors to “mutilate” film scripts is forcing top writers to either direct their own work or write for television, where they command greater respect.
... Writers’ Guild rules do not permit writers to take their name off a screenplay if they have been paid more than a certain amount. Studios can, in effect, buy their names.
It's not exactly news that writers get treated like dirt in Big Entertainment, but the way the noose has not only been tightened but lined with razor wire on the inside never ceases to appall me.
One of the advantages to self-publishing is that you get to produce exactly what you want. This is also its radical disadvantage: barring hiring outside help, you get nobody to tell you your word choices are stilted and awkward, that your grammar sucks, that you're writing for a nonexistent readership, that your cover design and font choices all stink. Not everyone who is strong-willed and determined enough to make their own thing and get it out there also has the wherewithal to make it look good, read well, reach people, etc. Sometimes other folks are needed for that process.
With moviemaking, though, the amount of effort involved to do anything more than utterly trivial all but demands you work with other people. The only way for someone to wear multiple hats on a given production is for the production to be extremely small. (Well, James Cameron did wear multiple hats on a couple of his jumbo-sized productions, but that was more a reflection of his personality than anything else.)
Someone has to end up at the bottom, in terms of how the vision in question gets compromised. Since the writer's the easiest one to compromise, it's no surprise it not only happens over and over again, but that each time it does happen, it gets a little worse.