> The hard part of defining requirements is being specific in them
True but I don't think you're accounting for iteration. You know the "idea guy" cliche? Today, if/when this "idea guy" hires a team of devs from India to make his million-dollar idea into reality, his inability to write good requirements will lead to a useless app, and the idea guy asking for changes (that are also poorly described) until he runs out of money, right?
Now imagine that his "dev team" works for free and can turn around each new set of requirements in minutes rather than months. How long will it take him to learn how to good acceptance criteria? A day? A week? It's hard but not that hard. And a million or two other "idea guys" are doing the same thing, and sharing notes with each other.