perhaps it is just that most of the games where i have spent a lot of time speccing have noclipping spectators. therefore, to me it is unintuitive to have spectators that do not noclip. i also know that most, if not all, mappers design maps to look good when in the map. i can forgive "un-prettyness" when noclipping, as i understand that mappers do not design for the benefit of spectators.
nux, what i meant with the statement you quoted is that, yes, you can make opaque walls, or texture the unseen side. having the unseen faces of the walls untextured is what spectators rely on to see into the interior of a room when no-clipped out of that room.
i'm no mapping expert, i only know the basics, but i do know most mappers do not texture unseen faces. something about performance or map size. this benefits noclipping spectators, as described above.
