It's because the developers of Rise of Kingdom wanted to give an equal playing field for everyone and decide not to monetize through advertising or any other unfair means and offer a fair experience. The initial price of the game is $0.99 and it only takes 40-50 hours worth of modding/hacking time to get all heroes, resources, gold, and gems. This results in saving $10-$15 easily just by hacking this one single mobile game compared to downloading multiple MOD APKs for different games which will result in spending more money on hard-earned cash.