It's like anything automotive. If the big manufacturers aren't willing to make it / sell it and kill themselves doing it. Then it'll never become main stream.

If everyones sparkplugs lasted forever, NGK would die an untimely death. They only want your plugs to last 50k miles, so you go out and buy some more.

We should all be driving around in cars powered by Water, but it'll never happen until we finally run out of oil. A friend of my wifes invented a gyroscopic engine that could be used in Aircraft. Rather than put it into production, Boeing just purchased the patent / rights to the product and locked it away. Made the guy who invented it very wealthy, but didn't do anything for the cost of a plane ticket. Same principle - It worked to well and would put jet engine manufacturers out of business, so lock up the idea so nobody can every use it. Dumb world we live in really.