I'd agree with you, except for the inexpensive and rational part. Considering the spiritual condition of most folks, the profit motive would hold sway over their disposition of their invention.
That's the single downside to the profit motive, in my opinion. When that rare time comes when it's necessary to sacrifice in order to truly benefit all people, the profit motive still determines the outcome.
Before you trace a tangent, I do not assume that the invention in this article is in fact a free energy device and not a fraud. I'm speaking philosophically.
I think perhaps you belong at another forum, perhaps DU. The simple lession discovered by Adam Smith is that the profit motive always works better than altruism in producing useful inventions.
History is full of attempts to hide production or technology to corner a market -- pineapples, tulips, lava lites -- all kinds of critical things. The trade secret is a recognized way of protecting an invention. But it just doesn't last. There are too many bright people with too many conflicting interests to keep free energy secret.
The worst thing is that this particular demonstration has absolutely no credibility at face value -- even if every word of the story about the demonstration is absolutely true, there is nothing mysterious to explain.