This is a very good analysis of a film I’ve admired for years.
It’s not really about the oligarchy - it is something deeper than that, but uses that ‘class’ as an exemplar of that deeper temptation. Plus they tend to look better naked than the rest of us do, at least in this film.
The term ‘oligarchy’ is not one we use over here much - we tend to go with ‘elite’ which carries many the same overtones. In a way, the use of the elite as subject to this deeper depravity is a kind of a forteriori argument that the ‘rest of us’ are even easier game. Not sure of that, though.