I love the quiet car on the NE Corridor because of the reverse commute--everybody pre-gaming for NYC. However, I avoid it on the M&E. I don't find M&E people that loud...
Took the Hoboken train home with my child. We were speaking in low tones most of the trip. When we got off, I saw the 'Quiet car' sign. Had no idea until that moment that we were in the last car (I forget those trains are shorter). No one shushed us (we also weren't speaking very loud-but I may have taken it down a bit more if I had realized sooner). But maybe the Hoboken line can be more sane than NYP.
The Hoboken experience in general is more chill than NYPS. I sit in the quiet car for the PM commute and have not once witnessed any confrontation.
I have a feeling vocalizations caused by a medical emergency are probably the quiet cops worst fears. A rational person fully under their control will stop making noise if yelled at. Someone that has lost the ability to control themselves won't stop making noise, which will lead to an untenable situation and would probably cause the quiet cops head to explode. I wouldn't expect much sympathy for the person with the emergency condition. Also, when the paramedics arrive, I'm sure they'll ask them to work more quietly.