I knew someone who worked for EA as a UX researcher. He said that games like these are primarily targeting whales who will drop $10k on a game. They are the real money earners. The really sad part was the he said the most whales aren't super rich, they're just people with an addiction.
They shouldn't be sold to children. They're not Kinda eggs nor LOL Surprise and should never be brushed off as surprise mechanics. They're glorified slot machines, through and through.