As subways are usually intended for traveling short distances, the passengers have to get in and out fast. Thus, subways usually have doors in shorter distance from each other than e.g. in train trolleys, that are used on lines where the stations are in larger distance from each other than subway stations usually are. The trolleys of double decker trains have stairs close to the doors, thus the trolleys for subways would need to have equivalently more stairs. Subsequently, the space gained for passengers to sit or stand would be much less than e.g. for double decker trains.
... You are on the train. The station you want to get off is coming up soon. You stand up. You walk down the stairs. You stand at the doors. So far this is all before the station you want to get off at. When you arrive at the station you want to get off at, you walk off. That solves the getting off quickly problem. You don't need lots and lots and lots of stairs to the point that it takes up more seating capacity than a second floor.
Being crushingly packed it a valid concern but yes it addresses his point. As does this: don't sit on the top if your station is one of the first 1-2 downtown, where you can't get down to the first floor.
His entire point is that subway trains have a lot of doors, leading to a lower seat/door ratio. Your response doesn't at all address that this ratio would change, or the actual repercussions of changing it.
In other words, you don't know what you're talking about, but you're acting like you do.
You’re very adversarial for some reason so ciao.
I am matter-of-factly telling you that you're not making a relevant point. If that's "adversarial" to you, then you need to get your detector calibrated.