There's a rumour that the maps are kept intentionally inaccurate, to catch copyright violations, but I've no idea if there is any truth to that.
I just multimap anyplace I want to go. keep to the Fen Causeway
I can confirm that, but the cartographer who explained that said it's in rather minor details (say, three roads meet like an Y in reality, but on the map, it looks like the top left one connects with a curve up to the top right one).
I don't know what's up with US maps, but I have a similar opinion. The only good maps are USGS maps (for detail; though often dated) and old National Geographic maps (for overview). About the latter, it's ridiculous that even while NatGeo is fighting for saving geography education, its maps over the 30 years I have (not all) issues from have become progressively more glossy and less detailed.
However, the Grid Deficiency Syndrome™ I meant comes from living in rectangular grid layout cities. Where I would get lost, one corner being like any others. This came up earlier on ET (can't find it), when it was explained to me that one shouldn't look at the unique look of local street geometry but at street numbering/lettering. *Lunatic*, n. One whose delusions are out of fashion.