I was wondering if you guys that are film makers care about mastering screenwriting or do you only care about getting your story on the page to go into production?
There really isn't much of a difference. The script is the blueprint of the story and movie. The filming is the construction. To say to ignore the script is like building a house without a clear plan. Especially when you start working as a producer and need to evaluate scripts, it's important to understand what you're looking for. Can you be an art critic without being a master artist? Of course. But art critics are also voracious readers and viewers.
I read about 2 scripts and then wrote 8 pages of a TV pilot introduction and posted it on Yahoo Answers and this person wrote a list of problems with my script.
It unmotivated me and I feel kind of lost when it comes to writing a proper screenplay.
Yahoo Answers? Enuf said! You need to read lots of scripts. And it doesn't hurt to take a screenwriting workshop. I'm confident that you're creative, but writing a script is different from writing a book. So it's good to learn about the formatting and the craft.
What situations is it important to master it? Do you master it if you're only interested in being a screenwriter? How about if you're interested in just submitting your own films to festivals? Or should you focus on writing a professional screenplay if you're going to write one in the first place?
As I said, the script is the blueprint. The formatting has evolved over time such that it is a great tool for knowing how long a movie will run, budgeting for cast and locations, developing a schedule for shooting efficiently, as well as aid the director in developing shots and storyboards. Mastering how to write a script is a critical skill. Having said that, it doesn't mean you have to learn all the nuances. Just like a builder needs to be able to read a blueprint and be able to make changes if something needs to be altered, the builder doesn't have to be an architect.
For most filmmakers, there are lots of practical books on screenwriting. It's worth having one on your shelf and use it to write a short film. I wouldn't attempt a feature until you've done a short. There is a LOT you learn your first go. And if you think criticism is demotivating, dealing with all the perplexities of a feature with no experience can be a major punch in the gut. There are releases, permits, expenses, scheduling and a host of obstacles. Try a 48 Hour Film Project. If you can't tell your story effectively in a script, chances are the film will not be much better. There is a reason that producers hire script consultants to revise scripts before shooting.