Passengers != manned. They aren't operating the vehicle, they're cargo.

even if that is the definition of manned it still doesn't make sense. because the "U" in UAV stands for Unmanned not Unpiloted. However "Manned space flight" would still apply even if the astronaut was just ballast right?

A trip to mars would be completely automated but you still wouldn't call it unmanned if a scientist was on board that did nothing but scientist stuff.

Which is exactly why 'manned UAV' makes no sense.

Yes but UAVs are built to an overall lower standard of reliability and safety precisely because there are no people on board.