There should be no difference in my ability to inherit 100 percent of my parents' intellectual work as 100 percent of my parents' farm. So, since I can create a farm exactly like your parents', and earn money from it, I should be able to make a copy of their intellectual work, and earn money from that, too.
But by all means hang on to the original :-)
You have my argument backwards.
If you can create (buy ?) a farm exactly like my parents' and make money from it, please do so. You would have no impact on me or my folks' farm. If my dad wrote a book and it was selling well and earning money and he willed it to me then you'd have little to say about my continued ability to earn from dad's work--just the same as you'd have nothing to say about what I did on my inherited farm.