In a way you are both wrong and right. You technically paid for the seat, but I take it that the driver would not be considered a rich man, so every bit helps him financially. You are both being selfish. Still, you paid for a service and he agreed to the arrangement so he cannot really be angry at you for it.
I love the Jeepneys and Tricycles though. They look really cool and practical.
You have a point sir. Unfortunately, the person that will ride next to me is bigger than I am and I had groceries. We will be both uncomfortable. Normally, I would be considerate but that moment was an exception. I was thinking if I had a companion that I paid for, will I have him be substituted by a stranger passenger? I seriously don't think so.
Indeed, the tricycles can easily be re-routed. The jeepneys have cheap fuel source and can accommodate many passengers.