How long did the Wright Brothers bust their butts before they invented the airplane, which they were told was impossible? Neither of them were scientists, either.
What about space exploration? It, too was considered impossible once. Boiled down, we really only did it out of curiosity. The benefits flowed from there.
The Pharoahs spend years building the Pyramids soley to have a nice mausoleum.
Humans will expend a LOT of effort on some things which, at the time, might seem trivial.
Could you imagine the furor if the Wright Brothers decided their invention couldn't possible make them any money? What would have happened if they had decided to keep it a secret?
I can only imagine what could have happened if they decided to pull some pranks by dressing up a Flyer with a body that portrayed something.