i believe the issue is that audible is marketed as allowing returns at _any_ time in the future, which is a pretty extraordinary return policy that leads to more subscribers. but then the producer has to shoulder the costs of this incredibly lenient return policy.
How is that different to deciding to sell your goods through Costco or Walmart and then complaining that their returns policy allows customers to return anything for any reason basically with no time limit if you complain enough?
Like, the author knows the policy if they decide to sell through Audible. It comes with a massive userbase, userbase which potentially exists because of a decent returns policy. If they think they can make more money on a platform which doesn't allow returns, then they are welcome to try - it's not like amazon has monopoly here, plenty of other places to buy and listen to audiobooks from.