Of all the zones, this one is probably one of the better ones to put surveys in. The Gold Coast is great as well. Why no surveys?! Why did certain zones get multiple locations for the same resource type but these zones get neglected?
The only "weird" one is that Summerset doesn't have any.
Coldharbour, Craglorn and Wrothgar having multiple surveys are relics of the pre-One Tamriel days when zones were tiered for their resources, surveys were unique (like treasure maps), and surveys depended upon the level of writ that you did for the zone you got (and where you did those writs).