Anyone thinking cedar is better without oiling either lives in a very narrow range of climate or is kidding themselves.
Oiling cedar is done to make cedar look like furniture, or to 'restore' the new(er) look of cedar - it its cosmetic only and does nothing to extend the 'actual life' of cedar as a deck, siding, or roof shake material. Once you oil it, you have an ongoing maintenance project, and you become the best friend of the Sikkens dealer.
Atlantic White Cedar (actually a Cypress) was chosen for early boardwalks in places with four season where wood is subjected to brutally humid summers and freezing cold winters. It is/was naturally rot resistant, and, because it could endure moisture indefinitely, folks started using it for siding and shakes. When they started running out of stands of material and prices rose, they turned to Western Red Cedar. Eventually the Boardwalk builders turned to Ipe in the 1960's because Ipe was said to last 25-years - in those brutally humid summer and freezing cold winter environments - with no finish on the material.
In the Pacific North Wet almost any material can become covered with moss or mildew on the north sides of buildings - folks power-wash it off and repaint where required.
The mistake people make with Cedar, is oiling it and or using it when something else is what they really want, but may not like the cost of. It all comes down to cost and how much time you want to spend re-coating your deck. I knew a guy that was a retired house-painter from the times when no one used a sprayer - his cedar deck looked straight out of the movies beautiful - he worked maintaining the like-new finish, every year...
But it sure did look beautiful!
