I have oten thought that it would be amusing to have a world where the magnetic poles didn't even roughly coincide with the planetary axis of rotation. But for worlds where the magnetic axis and rotational axis roughly coincide, that's a natural marker, as is an axis at right angles. True, the language labels should probably be different for different cultures, but for people who are labeling their maps in English for the convenience of modern-day map readers, it's a reasonable approximation.

Distance scales are again usually done for the convenience of modern readers. If you look at medieval maps that have scale bars, they will often have several scales labeled with the appropriate units. Scales really only matter for fairly local maps, so we don't normally worry about them on whole-world maps.

But I do agree with your point about people assuming infrastructure. There are many maps here where people don't understand how the world works well enough to even get water to flow downhill! Certainly, many people don't have even the basic understanding of how economic networks operate (which is why the roads are there in the first place) in the modern world, so I wouldn't expect them to get it for a world of their own devising. As a wise man once said "I don't know who discovered water, but it almost certainly wasn't a fish."