Is the issue really that the back of the bus is using the J "restroom" ?

It's not about the "restroom".

It's about having loitering people and high traffic etc passing thru the cabin.

For me , I could care less who uses the "Restroom". I think this post uses restroom in incorrect reference.

My belief is that the J cabin be kept free of traffic and people coming in and out and thru the cabin at all times.