Most lighthouses are cultural and historical icons, and they often faithfully reproduce the best technology of an era. Moreover, even if obsolete, most are wonderful architectural objects.
I can only applaud Norway's decision to preserve its cultural legacy. Shame others aren't as proactive.
-That it does, I zoomed in on my local area (I can see five sector lights just from my office window on the northwestern coast of Norway - they're all over the place!) - all are present in the map.
I love this map; would be even better if one could set opacity for the lights so that it is simpler to see the coastline details, though.
It's done to preserve the cultural legacy as the majority of lighthouses are obsolete.