Exactly. I don't have a problem with artists profiting from their work. I don't have a problem with their temporary exclusivity. The problem I have is when they never intend for that work to belong to the people; when they think they can maintain control over an idea long after it has become "culture".

For the problem you mention, I would suggest that any studio who has been offered the work during the five year period owes royalties for a 5-year period after the studio publishes the work, even if it has since entered the public domain. Something along those lines would likely become a standard clause between the screenwriter's guild and the studios, and doesn't necessarily need to be enacted in law.

I wouldn't be opposed to a longer period for some major works. Start with a standard, 5-year period from the time of original publication, then allow an extended copyright registration with an exponentially increasing annual fee. A few additional years would likely be affordable. The fifth, possibly. The sixth, only for the most profitable franchises, and the seventh being a large fraction of the national GDP. If James Cameron wants to pay for the entire military establishment through the proceeds of Avatar III, he can get one more year of protection.