I don't think anyone buys a game only because they want rewards or trophies... I think they buy the game, because the story or graphics appeal to them... But that's just my opinion.
I know people that do this. But those are a minority and it's beside the point completely and thus irrelevant.
It seems you're also thinking in absolutes a lot, which isn't helpful at all.
Maybe I wasn't clear in the post where I brought it up.
Yes, generally people buy and play games because the theme gameplay, or story etc. appeals to them. In recent years games have become more reliant on unlocking things and using those methods to keep players engaged. It's not that people generally play a game to get all the achievements. But through play the player will become hooked on the rewards and achievements that are fed to them. And once this feeding of rewards stops, at that point the player will have become somewhat dependent on it and their engagement and even fun will decrease. In a scenario where you'd have mostly the same game but without the focus on feeding regular rewards/achievements and if the player found it fun to begin with. What would happen is that the player would just play for play's sake and they wouldn't be bothered by wanting the next reward. In other words their enjoyment will be less tied to extrinsic rewards while with the game that relies more on rewards and achievements the intrinsic enjoyment will morph into extrinsic enjoyment that is depended on those rewards, supplanting the intrinsic fun.
It's well known how and why these things happen. Most people don't even realise that such a thing happens. But it definitely happens (to a greater or lesser degree of course, as some may be more susceptible to such things than others.)
