I don't get quantum computers. Why build one? What's the point?
They only talk about destructive purpuses: "with a quantum computer we can break this or that".
If it's only useful as a doomsday device, then stop trying to make one, dammit!
Lot's of things were invented by ... by their inventors for altruistic purposes. Explosives, Dynamite, the atom-bomb.
I believe there will eventually be quantum computers, but they'll never break 256 bit encryption as we know it today, or rather they won't be able to brute force it. They will break something else, or find some weakness, but it seems very unlikely.