I agree , it's also not normal to be able to see everything behind closed doors .
I didn't realize how much of an issue I had with this until you mentioned it.
In general, it takes away the mystery. In the case of locked or sealed doors that require effort of some kind, being able to peek into the next room kills the danger and anticipation.
Even if you couldn't see who or what was in the room specifically, getting an idea of the layout and architecture kinda breaks the feeling of adventure and exploration.
Add this to the list of reasons why some type of fog of war or rendering distance slider or option would be great!
