For the consumer who just wants to connect their device to a HDTV, it's crazy they have to pay 10x more just because they're in the Apple ecosystem and not Android.
As for being future-proof, by the time some cool new A/V interface hits the market, and we've all updated our TVs, the Lightning devices of today will be in a museum.
And economy of scale does work. I do not think Apple can seriously undercut Samsung because they managed to leave out a HDMI chip.
I think Apple's reason for this connector is more one of aesthetics: why have X > 1 chips that can communicate with the outside world and, typically, X connectors? Full wireless is not yet an option, so they need one. Then, they need some way to figure out what is on the other end of the line.
Why they didn't pick USB3, I don't know. Not proprietary enough? Connectors too bulky? Low power spec not (yet) available? Not flexible enough? Supports too many devices? (If you put an USB connector in, people will expect that it works with their hard disk, photo camera, keyboard, mouse, etc)
Why? They'll plug another $50 adapter on it and it'll work.
And that the original dock connector first appeared in the iPod 3G nearly a decade ago. So yes today's devices will be in a museum. But the connector could still be in use in 2023 and beyond. Worth keeping in mind.