maybe because they're afraid it would take too long to fight their way to the front and they'd miss their stop cuz they couldn't get off in time?

When I got on the bus, there were four people standing. All of them in the narrow space right by the front door. And they wouldn't move to allow me to get past them (I forced my way through).

And, because I was trying to be polite and got my way to the empty part of the back of the bus? I did miss my stop because the crowd just wouldn't move.

I really think it's that people have terrible bus etiquette.