I think you're broadly correct and that's definitely a reason, and I have another example to support it.

Mumbai too has a very similar structure (the core city is basically a peninsula that goes north-south). Our railway lines run N-S as well, with (till the recent Metros) feeder roads connecting them.

Mumbai is also one of the most densely populated cities in the world (#2 by some metrics).

Our local railways have an annual ridership of 2.26 billion [1]. Pretty much everyone agrees they're vital to the city.

1 - https://en.wikipedia.org/wiki/Mumbai_Suburban_Railway