It's worth noting that they got there because at the time of development, the rail companies were able to buy up the surrounding land and develop that. They reinvested their real estate profits into more rail and more real estate, creating a virtuous cycle. (Hong Kong, one of the only other profitable systems, did something similar by having the government effectively transfer land for free initially.)

American rail systems largely didn't develop around their stations, and if they bothered to develop around their stations they sold the land after construction and that was it. For them to do so today would require billions, if not tens of billions of dollars to provide fair compensation for eminent domain for land and property around stations. And that's before the legal costs to fight all the resulting litigation, if they even were allowed to do it.