Shouldn't the dev be focused on building the game instead of a new cryptocurrency?
I'll be nice because you seem cool. The dev is focusing on building new games namely Hero's and Project Rebirth. And has already completed Apex. Jewels is going to be the currency of his games and hopefully many others games of the future.
If you read the op and listen to him in his video, and browse their twitter you'll understand how much potential jewels has for future growth.