O-1A: very hard to get in business without either a letter from a senator/governor or a long history of speaking gigs (according to my immigration lawyer).
The other (and apparently more common) way business folks get O-1 approval is an endorsement from a high-level government official. My lawyer was reasonably confident that if I could secure financing and demonstrate potential this would be possible, however I'm not comfortable working that hard for that long only to be held up on the whims of a senator in an election year, particularly since I couldn't incorporate without having status.
It's frustrating but understandable. The UCIS has no way to evaluate "Extraordinary Ability", so they can only go off your perceived position relative to your peers.
Both of those options were suggested by my lawyers, and once you realize it's possible and common one starts seeing it everywhere.