They discovered in user testing that about 20% of the population cannot rotate a map in their head. So they rotated the map in software. Keeping the labels in normal orientation was tough. Now everybody does that.
The navigator uses the maps to produce instructions for the driver which will be things like sail in this particular direction until we pass that specific island then turn some specific amount and so on.
The navigator doesn't even have to look outside while doing this, and all the directions are specified by compass points, so of course a north on top map makes sense.
For a car nav system the nav system is both doing that high level planning that a ship navigator does and is doing very low level navigation for the driver, and the driver is executing the plan by looking out the window and matching what they see to what the plan calls for. Also events are happening much faster in a car, because (a) cars are typical traveling faster than boats, and (b) cars are typically in environments with a lot more obstacles, and (c) those obstacles are more closely spaced than typical ocean obstacles. For telling someone how to turn right now most people will do better with "turn 90 degrees right" or "turn left at the upcoming intersection" than instructions to change their heading to a specific compass direction.
So far a car nav system it does make more sense to make the nav device's view match more closely what the driver sees.
Ideally I'd like something that switches views depending on the situation. Say I'm driving from the Seattle to Los Angeles. When I'm cruising down I-5 a north up map view zoomed out so I can see the big picture would be great. If I decide to stop in Sacramento for gas and a snack, then switching to a smaller, current direction up, view just big enough to show my current position and the gas station when I exit I-5 would be more useful.
Yea, getting off some of the interstates in Texas has situations like this.
You are traveling 60-75 MPH then you exit interstate right, then you quickly split on an capillary highway that splits to the left, then moments later split to the right again then have to get in the right or left lane for a turn depending on which direction you're heading. All while having local traffic that knows the traffic pattern fly past you where it's more than one lane. I swear it feels like one of those space fighter games where you're attempting to avoid asteroids and other ships at a fast pace.
If I asked you to draw a map of the room you’re in, I highly doubt you’d orient the straight angles of the walls with respect to the angle of your body. You’d draw them along a compass rose relative to the structure. Rotating a map to your gaze is actually not very intuitive when your goal is to usually to transform the world to be outside of your reference frame.
The transformation of the map into your perspective is a last-mile problem: it’s important when you reduce your decisions to “what landmark is in front of me, and what is to my left and right?”
Someone else said elsewhere on this comment section, if only a navigation app would also show the position of the sun at that moment. If we already have the compass directions, the direction of the sun can be an extra UI element.