Helen
Inkling
Has anyone else ever had one of those times where you're watching a Tv show or movie, then start to put thought into the story and think to yourself "I could have done better"? I've had many of those moments, and i've started to call this feeling "Writer Arrogance", because i think that i'm being a bit arrogant for thinking that i can do better than professionals.
Most movies, whether based on a fictional work, factual or mythological get it wrong, wrong wrong! This is why I watch very little of the crap.
a) You're assuming you have absolute creative control all the way through. You don't. Not by a long shot.
There are ways to increase your creative control leverage - get the director gig or go in with a bestselling franchise etc - but those have even longer odds than selling the script.
b) There's data out there which compares the number of consider/recommends scripts get with the number of passes. And it turns out only about 1 in 100 gets a consider, let alone a recommend. Taking that at face value: writers think they can do a better job than they actually can.