the author could be alive, and write new works, and that seems more likely
any member of the family could also contribute to society by writing new works
remember the goal: to promote new works; not to make the author money, or their family money, or their family's descendants money; and not to enrich or prevent the enriching of any given publisher
allowing the author and family to milk old work in perpetuity, whether independently or through a publisher, would seem to incentivize the opposite of that
In some ways, writing a novel (or producing certain types of works) is like buying a lottery ticket. Most of the time it will be worth nothing. But if it is a winner, then the buyer would like to be able to cash it in. If, on the other hand, you couldn't win the jackpot even if you hit all the numbers, then people would stop buying lottery tickets.
The purpose of copyright is to encourage people to write or produce creative works, even when the reality is that most works will not be successful in any way. If you take away the possibility of reward for the few works that are successful, then that will result in fewer works being produced.
nobody is proposing "taking away the possibility of reward", or making anything such that "you couldn't win the jackpot even if you hit all the numbers", so it sounds like there're no issues with the proposal
if there was data that shows copyrighted works usually earn nothing the first 5 years, and earn significant value after that, or even that annual earnings from copyrighted works usually increase after 5 years, the argument against the proposed reform would be more convincing,
but in any case, the purpose of copyright is to encourage new works, not allow authors to perpetually cash in on old ones like a lottery ticket instead
any member of the family could also contribute to society by writing new works
remember the goal: to promote new works; not to make the author money, or their family money, or their family's descendants money; and not to enrich or prevent the enriching of any given publisher
allowing the author and family to milk old work in perpetuity, whether independently or through a publisher, would seem to incentivize the opposite of that