What it means is they'd have to focus on the thing they have that can't be copied: their skill and talent. In other words, their labor.
But who's going to pay someone to create a product they can't sell? I think reducing this to case a abundancy/scarcity might be oversimplifying the issue.
We might need a novel system of middlemen to pick the wheat from the chaff, or a new payment model to allow millions of individual gamers to fund development rather than a handful of investors, but there's no reason to think selling copies is the only way to make money.
Doesn't the current system already fund this development?
To the landlord belongs the doorknobs.