The deeper BS is that there is no engine. People remember the XB-1 demonstrator flying and assume that Boom is farther along than they really are. The XB-1 had off-the-shelf GE engines.
Booms claim is they're developing and will some day real soon have "one that works" and then it can be produced at a low-enough cost in sufficient quantity.
Yes, it's dubious.
I could off the top of my head name a few rich people that died from it. Hell, the titan submersible, while a very different animal, is a pretty clear indicator that vast wealth doesn't preclude a willingness to risk one's life in highly experimental "travel"
It'd be hard to spin that as being anything like as heroic as the risk of being killed or maimed whilst climbing Everest!