Most probably because that tiny glider with a rocket bolted to it, is pushing more / has more dangerous limits than a subsonic airliner.
It's much faster to go outside the designed flight envelope if you're 3x supersonic at FL800 than cruising subsonic at FL320.
I don’t think anyone disagrees with the general assertion that rocket travel is more dangerous than airplane travel. The question is less “is this rocket as safe as an AirBus” and more “is this rocket as safe as other rockets?”
My issue with Virgin Galactic is that their rocket design is fundamentally unsafe. It requires a human crew flawlessly perform a high level of work load with minimal automation and safety interlocks. This isn’t something we’d accept with a commercial airplane, even with the much wider margins of error that those craft provide. For a rocket this is absurdly dangerous.
The designer in fact explicitly said he wants the pilots actually in control of the aircraft directly without automation, which is romantic but incredibly dumb during supersonic ascent, as the fatal crash shows.
