I guess it depends on where when and where you ride the bus, but every time I get on a bus in San Francisco its overflowing with people to the point that they have difficulty closing the doors.
That's because you want to ride on the popular bus routes, which isn't a coincidence. If lots of people wanted to ride on the empty bus routes, they wouldn't be empty—they'd be the overflowing ones!
That depends on the municipality- I’ve definitely lived places where a goal of the transit system was “access” even if the buses were nearly empty on some routes. I’m not sure it’s an invalid goal eithier.