That Wikipedia article doesn't make that claim, and normalized by GDP actually contradicts it by pointing out that 5 of the top 10 of those cities actually have well-developed rail (I'd add DC and Atlanta to that list, bringing us up to 7 --- in other words, leaving out only LA, Houston, and Dallas).

I disagree about Atlanta. Atlanta does not have a well-developed rail. I should know - I live there. :)