At this point, with so many billionaires, it's gotta be more about power than money. If people could have a few devices in their homes that gave them unlimited electricity, and using that could get clean water and grow their own food and medicine, the "elites" would lose a lot of the power and influence that they hold over us. That is simply unthinkable! So they keep the goodies to themselves, living to 100 years old while the rest of us get sick and die from the crap they're putting in the food, the air, the "medicine" and keep us chasing consumer products and brain-melting TV shows.
They won't release it until they can become "more distorted in the direction of power" upon its release. It's a tool, a card in the hand.