I think his point is that if commutes were quicker then regular people could move away from the city but still work there. Billionaires could still sell real estate to each other then without hurting lower incomes.
Edit: As an example - in my neighborhood there are $300k houses in pretty sorry shape that are purchased just for the land. They are destroyed and then a $500k new house is built on that land. This is what I'm facing. I could perhaps afford $300k (although I'm gunshy to purchase in such a volatile market), but it would require IMHO another $50k in renovation to make it "livable". I'm not talking about granite counter tops and high-end designer furniture, I'm talking about roof, insulation, water heater, bathroom fixtures, yard work, etc.
275 sq. ft. with "a half refrigerator, 2 built-in electric burners, and a microwave oven"
I'd bet once a decent public transportation system is inline, the termination points of the larger trains will become as much city-like as the center, but much more affordable.
It is expensive though.