It's only a great concept if you assume that subway's some kind of mythic being reserved for other cities. And yet we were given enough money to get huge lengths of subway even at the ridiculously inflated price of $350 million/km, and we get lines prioritized in no logical way whatsoever, that doesn't think for the future at all. Would I rather have 10 km of subway that's going to benefit half the city hugely for decades, if not centuries, or do I want sprawling lines going out to the middle of nowhere which make a tiny dent in transit deficit, and make no concession for the very real future needs of the city? Transit City is a band-aid solution. A band-aid solution when we can actually be getting a bit of what we need.