To be fair, his goal was apparently to send a stern warning about the evils of entitlement by murdering them in ironic ways.

Also, the rich, spoiled, first world white kids aren’t presented in the story as having gotten the tickets by chance, the story is very clear that they and their families used their privilege and power to game the system - taking what was initially presented as a random selection and cheating by leveraging their disproportionate resources - wasting mountains of chocolate in pursuit of gold…