And that's the case with most things. See this video, for instance. It's about the jetpack and its inventor, Justin Capră.

Toward the end of the clip, he mentions that an American told him new cars or new energy cannot be implemented, although technology allows, because that would mean millions of people losing their jobs. Tomorrow.
Obviously, that's not such a great idea, but what that actally translates to is:

Some people invested a lot of money in today's -- or, rather, yesterday's -- technologies and they want to maximize on their investment. So change is hard, if not impossible, in this case. I'm sure you know the whole PCI versus PCIe and PCI Express. Even though PCI Express is better than PCI by leaps and bounds, it could not be implemented right away because big players had invested money in PCI -- the legacy system. This is also the case for electric cars. Well, that and the fact that they're damn expensive and have low autonomy.
Still, we could work on their autonomy and find a way to drive manfacturing costs down -- but nobody's interested in doing that because there's still plenty of money in the oil business. Only when that pot boils dry will we have an urge to improve the alternative energy sources.

The coding-world example would be Python 3 versus Python 2.x. No backwards compatibility! A rewrite. Because things got out of hand. The API became a mess. And with great cost, they brought forth a great change. A New Age. And yes, if other new ideas -- in other idustries, I mean -- would get implemented like this it would cost a lot of people a lot of jobs. Jobs that would be replaced by new ones, yet nobody's talking about that. And yes, the filthy rich that invested in the current technology would be a bit less rich. So why don't they invest in the new one side-by-side? Like a pet project. Or like a common fund investment.

To go back to Justin Capră, his merit for inventing the jetpack is finally being awarded to him. And that's good. What I loved most about his discourse, was how he sees automobiles, as shameful devices. They burn 980ml of fuel to move themselves forward, and only 20ml(!) to move the 1 person they bare. That's not a good ratio, by any means.

Screw the MPG fad. Focus on Gallon Per Ton Per Mile for a while, eh?