why marketing objectives aren't rocket science

All marketing campaigns should have one of two objectives - market share or market growth.

If you are already the dominant bus operator in a given area, then your objective should be to promote the bus as a product, rather than you as an operator. If you're successful in doing this, then by default you will increase passenger numbers. 

More people getting 'the bus' means more people getting 'your' bus.

However if you aren't the major player, your objective should be to take market share away from the operator who is -  telling people why your bus is better than theirs.

If you promoted the bus as a product you'd just be giving your rival a bigger slice of a bigger pie.

And that's pretty much it. Like I said, not rocket science is it?