I don't think Elon is opposed to the Oneill vision of living in space. Note the last part of the ITS presentation. He just thinks that mars is the best place to start a self-sustaining colony at our current technology level.Jeff Bezos seems to subscribe more to the Oneill vision. See this article. So we got very wealthy people pursuing both approaches.Ultimately it boils down to transportation. If you have cheap transportation, enabled by full and rapid reusability, you will have both. If you don't, you will have neither.