Because they didn't realize that the mechanism of the game make there pay for playing like it's a coin machine.

You can't compare micro transactions in game that you already pay and candy crush, you didn't pay for a full game, if people want spend their money they are free to do so, I'm also free to call them dumb for that reason. I personnaly play CS:GO sometimes and I have sell all my skins, cases, etc., and thus make the game free for me more that 15$ earned, then I can only say that others people are a little dumb to pay for that.