I am in favour of fixed lengths. Perhaps 50 years. Then, even if someone miraculously writes something at age 0, they could still be receiving money for it until age 50. And if they write something in their 20s or 30s, then they'd have the copyright into their 70s or 80s. Seems perfectly fair to me.
While I don't spend much time worrying over it, I'm not in favour of "Life plus X years" policies and I'm really not sure how it became a thing. I just cannot fathom a work written at age 24 by someone who dies at 95 receiving a copyright that lasts 70 years longer than a work written at age 24 by someone who dies at 25. For "life plus 70", for those examples, one copyright would last for 95 years while the other lasts 165 years. Does this sound fair?
"Either/or" laws where Life+ and fixed length are combined are a step in the right direction, but still I don't see why someone that lives longer should enjoy a longer copyright just because. It doesn't seem fair or necessary.
I couldn't care less about an author's grandchildren being provided for by the copyright 100 years down the line. They surely would've heard of a thing called "work".
When you think about it, many laws are either "life plus 50" or "life plus 70", and so if an author wrote a smash hit and died the day after publication, their heirs would only get 50 or 70 years anyway, so really no different than a fixed limit of 50 or 70 years. The only difference is that with "life plus x", authors who live longer would get more years (and money) for their copyright for themselves and their heirs. Doesn't it seem doubly unfair that authors struck down young also have the ignominy of their families receiving a much shorter overall copyright than an author who has the luck to live longer? In what world does it seem fair that the family of an author who wrote a hit at 24 and lives to 95 be able to receive moneys for a quarter of a century longer than the family of an author who writes a hit at 24 and dies at 25? I say a fixed length is much fairer, and though I'd err towards a lower number, I'd still be more in agreement with a fixed length of 100 or 150 years than "life plus x".
If you'd like to argue that the "life plus x" is a fine length even if the author died the day it was published, then how can you possibly argue that a fixed length of that same "x" is too short, since in that example they'd be the same length? Or how can you possibly argue that "life plus x" instead of "flat length x" is necessary for the rights of an author's heirs when the heirs of an author who dies the day of publication only receive a flat length of "x" (and to add insult to injury, those poor heirs may very well also have less works to receive moneys from since that author would've died much sooner and had a shorter time span to produce works).
But let me tell you how I really feel.
Honestly, it's just one more thing that doesn't affect me much, so I can't worry about the world. If Mickey Mouse makes copyright 1,000 years long eventually then oh well; I'm sure at that point there'd be discussion threads out there somewhere with people defending a thousand year length as necessary to provide for an author's family tree and such. And I'm fine with that. And I like Mickey Mouse despite it all, so there you have it.