By your argument, I should be able to directly copy a book and sell it myself. The work was already done! What's more, they were fed by everyone's creativity, so of course I should be able to sell an exact copy.
In reality, the short-sighted greed is allowing widespread theft of intellectual property; do you think the number of writers would increase or decrease if there were no protections against content theft?
If you have such "immense gratitude", pay for the work.
Most likely increase, despite your intuition. This argument has been debunked so many times both intellectually and empirically. For one, read "Against Intellectual Property" by Stephan Kinsella.