The reason people play these games is habituation. By placing delays on things, they encourage you to take the content in small doses, and thus build a habit of

The reason people play these games is habituation. By placing delays on things, they encourage you to take the content in small doses, and thus build a habit of playing, rather then burning through the (relatively small) amount of content quickly. Once people have a habit, they will rationalize it... "I am playing this, so it must be fun". Even once the content and new game play runs out and it is reduced to a rote grind, people will continue to play because of the sunk costs creating an unwillingness to abandon all the weeks or months of grinding they put into the game. It is a model pioneered by the MMO industry, but taken to an even greater extreme, where some of the worst psychological traps that people get stuck in are used against their customers to extend their profits.