...only if you apply the code. It's entirely optional.

Well that's a salad of opinion, but this is not only the first time a game-breaking option has been available on some marketplace interface (most mobile games?), literally not making it literally the worst DLC, but -as with horse armour - is completely optional. Although with horse armour, you had to pay extra after…

In no way is this worse than horse armour.

Not to mention that crowdsourcing their funding not only secures a consumer-base, but ensures they stay independent, without any of the design overhead that can cripple fairly original products like this.