From another point of view, some people are happy to support the devs of the game with IAPs, what is not cool is tricking people to spend money to play the game

From another point of view, some people are happy to support the devs of the game with IAPs, what is not cool is tricking people to spend money to play the game (eg. 1 coin to continue) or to progress in the game (eg. 100 gems to upgrade to a better weapon so you don't have to farm for 30 days).