[kijin]

The hypothetical plane can only carry a dozen people at a time and burns a lot more fuel per mile than a comparable subsonic aircraft, so the tickets will be very expensive. Most people will not be able to justify the cost, even most business travelers.

[amelius]

Yes, but fast forward 10, 20 years into the future.

[kijin]

Unless the cost of oil goes down dramatically, the only way for hypersonic flight to become affordable for the masses is for new technology to achieve drastic fuel savings. If that happens, there would be no reason to oppose it any more than one might oppose "regular" air travel today.

Commercial airlines have an extremely strong incentive to reduce carbon emissions, more so than virtually any other industry. I wouldn't worry too much about aviation tech moving in the less efficient direction.