"Scientists and engineers make a healthy living out of 20 year patents"
There's a big difference - which is that creating whole new works based on a patent is far more difficult and expensive than simply copying someone else's work and distributing it to make money - especially today where digital copies made copying and distribution costs close to zero. Evidently, in amanuenses times, copyright was a far smaller issue.
Also, as explained elsewhere, some make millions in a few years (even months) from a work, other could make little over a far longer period of time. Shortening copyright length will greatly favor the former at the expense of the latter - which are usually those making far less money.
I wonder how many talking about what copyright should be actually created at least once in their lives something that has value for others, and how many just hoarded other people creations without ever creating anything.
Because it is far easier to tell others should have no rights when yours are not impacted...
BTW: you know, for example, what could happen if the Linux kernel copyright expires? <G>
Biting the hand that feeds IT
