I agree that life+70 is too long, but just 7 years seems pretty short. I'm interested in hearing your rationale for choosing that number.
7 years seems short, but revenue capture must balance with the cost to society of copyright. Thus, ~80% of the revenue for 200x the freedom is a viable trade off.
PS: Remember the constitution explicitly says it's to promote the creation of new content NOT extract money from existing content. Having an author extract residuals for 50 years discourages new works.
A real-life example: The Notebook (the book) was published in 1996. The Notebook (the movie) was released eight years later, in 2004. With a seven year copyright, the book would be in public domain, and the author may not see a dime from the movie. Is that fair? Is paying the author of the book royalties from the film's revenue a burdensome cost to society? I assert that the author of the book should be able to earn money from the wildly successful film adaptation of his movie, whether he's directly involved with the production of the film or not.
I'm sure there are a lot of subtle technicalities I'm missing, but I think the core of this argument stands.
I'm in favor of reducing the duration of copyright, but I think something in the region of 30 years is a more reasonable amount of time than 7 years.
Regarding the constitution, I think that the means of promoting creation of new works is the ability for creators to profit off of their works. By reducing the potential for profit, you reduce the incentive to create. I can see how overly-restrictive copyright law can inhibit creativity, but I think a 7 year period swings too far in the opposite direction.
Further, some authors make their first book free on Amazon in electronic format in what amounts to advertising for their second book. As long as an author can 'make a living' being an author you need to demonstrate the need for additional revenue when they are not writing.
Only a tiny fraction of Music, TV shows, Books and movies get revenue over a very long time period.
It's also my understanding that book titles are not protected under trademark law, except for the title of a series, so The Lord of The Rings could be trademarked, but not The Notebook.
Anyway, characters can also be trademarked, so you could have a magic school in a movie that's not named Hogwarts and a little boy not named Potter etc. So, you can have similar stories using different charters, but your forced to produce an original work and not use or imply 'based on X'.
There are also rules that let you use others trademarks. So, you don't need to pay using a ford car in a movie, or having an older song on the radio.
We could also have a longer copyright that caps to 7 years after first sale or public performance.
My point is simply there is a lot more flexibility than total control forever, that still preserves artistic control in their lifetimes.
I will, however, point out that they are very much not doing that.
Now, my sister actually makes moves at Disney so I am well aware they do make new content. But, their model is very much based on milking old content and then waiting for new content to be fond childhood movies.
Snow white is from 1937 so they put out Maleficent which was somewhat original. But they also just remade Beauty and the Beast from 1991.
And there are many different forms of innovation. For one, the technological innovation needed to bring the new Beauty and the Beast to the screen. You could also say the same thing about The Jungle Book from a year or two ago, yet the technological innovation to present the story in the way they did recently is miles away from what they had when they made the original animated film.
Whenever people give up power without gaining enough you can expect a backlash. Given the option I would vote to end copyright and I am not alone. Everything after that point is a compromise on my part, especially when Shakesphere had zero copyright protection. Just picture the music that rises to the top without music promoters.
You talk about "giving up power", but be honest: what power should you have over someone else's creation? Why should you get to use their creation, or why should you get to tell them how to use it?
"Just picture the music that rises to the top without music promoters."
It would be exactly the same, because music promoters would still exist. The existence or non existence of copyright is not going to change what's popular. And the existence of copyright does absolutely nothing to stop you from trying to make something new.
I stopped writing a book that happened to be overly close to another book someone else published. I had not read it when I started, but reading the second book I could no longer really separate the ideas. Now, sure plenty of people keep going in that situation but technically it does not take much to cross into derivative works. It's also why may (but far from all) writers stop reading others works.