I get that this game is designed to make money but I disagree with making chances to win for players a random event.
This game is now becoming a game of chance and is taking away from people being able to boost their stats with gold. This creates player dis-satisfaction. When players are not happy they leave. On the contrary, if the events were gold spend based with sure payout then those that spend to achieve those goals are happy. Creating customer loyalty. Increased loyalty leads to increased profits. This is a win win situation.
People spend whatever they are comfortable with in this game and should not be penalized by random occurrences.
For example during this last boss event, I would rather have to hit the final boss 100 times for 1 kill but get a prize than to kill 50 extra 100 bosses to get junk at the hope of getting a prize. Same spend of gold but one situation creates loyalty and the other creates posts like this.