It is helping the developers. It is getting them a broader userbase than they would otherwise have by having it promoted front and center on the app store, and also it being free. I think it is pretty humorous people would assume they would just get free money from Amazon for this.
As these developers discovered, all a broader user base brought them was increased infrastructure and support costs, with zero uptick in subsequent sales.
"A broader userbase" that doesn't pay anything isn't "help" by any stretch of the imagination for a number of business models.
