> Why can't we put a camera by the emergency breaks?

This is a subway system that still runs on signaling systems built in the 1930s. The MTA is exceptionally slow moving and incompetent.

The way I understand it is that emergency brakes are for when the train desperately needs to not leave the station. Either someone very sick is on the train, or someone dangerous gets on, or there is some other emergency. When that happens, you need a way to absolutely 100% prevent the train from leaving the station, where help is most readily available. Unfortunately this requires trusting passengers to not pull the emergency brake on a whim