The idea of SpaceX being public makes me very nervous about the future of commercial space (though I really, really want them to succeed). Think back to when NASA lost people (Apollo 1, Challenger, Columbia) - these were seen as huge national tragedies followed by years of public scrutiny and gov't inquiry. But work pushed on, because their funding and momentum to continue with operations was decoupled from these reactions.
Now, imagine the first time SpaceX loses a human. If they are public, that could kill the entire company right there. Stock traders are not rational actors.
Consumption goods, not investment goods.
How do you convince ~100k people to pay 500k each to go there?
Back of the envelope Drake-like equation:
• Minimum wealth of richest 1% of Americans: $8.4 million
• Of those, 1% are in good enough mental and physical health to go
• Of those, 1% actually want to go.
That's 30,000 people. Obviously those numbers are seat-of-my-pants. Maybe only 1-in-a-thousand of people capable of making the trip want to go.
EDIT Tomp is right, my math was wrong.
In terms of compensation for the colonists, what are you going to do with money when you're on a dead rock 225 million kilometres from Earth?
What hasn't been talked about much (probably because it's a decade or two away and thus quite speculative) has been the economics of colonization. Yes, money can be raised for an expedition perhaps with public/international/crowdfunding assistance, but then what? What profit or economics will drive colonization? Would the chance of establishing their own new country be enough? How do you convince ~100k people to pay 500k each to go there?