I imagine the odds are that Boom will most likely fail, but if wealthy investors want to pump money into supersonic flight R&D knowing that the risk is high, then I'm all for it. If nothing else it's very cool.
The model for all of these aerospace startups is to just develop something interesting enough for an acqui-hire. Boom will never build a passenger jet. But some of their tech may make it into the next generation of GE engines if they're successful.
Ferengi Rule of Acquisition 35: Peace is good for business.