Sure, there is a place for in-app purchases. But there has to be some moral code involved. I think that in general, paying for consumables is bad, but paying for extra (permanent) features is fine. There may be exceptions to this. There's this website, http://honestandroidgames.com/, that has its own moral code but it is quite restrictive (must have no ads, must be either free, paid or free with a single IAP that unlocks the full game.) I wonder if it is possible to come up with a more flexible moral code for game monetization.
No, there absolutely does not. The only way to filter your game usage through a moral filter is to subscribe only to things like honestandroidgames.com, which is akin to programming out all non-Christian TV channels in every TV in your house.
Those aren't a moral code, they're editorial policies. Even if they were moralistic, the only thing that is summarily prohibited is "Bum Fights Video Library" type apps, which is a nearly-nonexistent bar.
> I wonder if it is possible to come up with a more flexible moral code for game monetization.
Sure: come up with your own moral preferences and (1) as a producer, don't make games that violate them, and (2) as a consumer, don't pay for games (or IAPs within games) that violate them.
This is a complete hypothetical, but how do you feel about consumable hats?
I'm thinking something like you spend real dollars on a hat (or other item) that does nothing but change cosmetics, but disappears after a week/month/quarter/year.
That doesn't sound too bad... It's definitely not the same as using psychological tricks to coax people to pay. As long as the game is not designed around getting your money, it should be okay, I think.