Rules, setting, system and high concept vs purist for system

In Rpg Theory Valamir presented this thread, Setting as rules . The concept was well received and seemed to go uncontested but it got me thinking. If setting material is really a part of the rules of the game and rules a part of the system (in the full Lumpley principle sense) then the two different types of Sim play, High Concept and Purist for System arent really all that different. High concept sim really is the sames as purist for system just with different types of systems, one that relies much more on setting and theme and less on mechanics.

Sim play uses the system created to enable a discussion based on the tenets of the system, the rules both mechanical and setting/theme based. This differs from both gamist and narrativist which view the tenets more as color used in pursuit of either step on up or story now. System in sim acts as a boundary to keep the discussion on topic, it both defines the topic and the way events happen within shared imaginings about the topic.

Any thoughts/comments?