Why ?
Because there are tombs everywhere in SKyrim with nords inside , some are family tombs , but then you find there Corpses like catacombs , Urns with dusts but also there are the rytes of cremation like for Kodiac and the other olaf One eye if not wrong ... so which one is actually used?
both ? one? a mix?
I ask this to understand then the use of Tombs and have a more logical interpretation , I guess bethesda didn't even care about thinking of this just copying some viking traditions and mixing with the need for Ancestral tombs to explore ...
So what you say ?