I'd argue that (a), it's not, and (b) we're not doing trains at all. It's just another road for cars, this one's just underground.

It is interesting to me that so many are hung up on form factor. It is like is has gotta look like a traditional NYC or London subway train (complete with gum stuck under the seat I expect) or it can't possibly be any good. It should just be about speed and amortized cost per unit distance.