^ That's what I'd like to know
Actually, to be absolutely honest, I think it all comes down to the market.
Take the S class interior for example, it is so middle-class in terms of its aesthetics. This is primarily because the vast majority of the market has very middle-class taste.
This is not a criticism ....it is just the way it is.
When I use the term 'middle-class' or 'bourgeois' I am not speaking specifically of socio-economic status -- but purely about the tastes which make up the widest group of consumers who will own an S class.
I will be more specific and suggest that it is predominately tailored to the middle-class tastes of an affluent North American market. This is the market which dictates that the interior must still contain wood (for example) ...but also dictates the subtle retro elements which make very direct emotional connections with the observer.
This is a very good example of what I would call 'bourgeois taste' -- this represents the widest market for a product like the S class. It is very status-conscious ...containing archetypal elements which have deep-rooted cultural references to affluence and preconceived notions of 'good taste'.
Designers are influenced by what is happening at the very highest levels of culture -- a lot of compromises have to be made when translating these influences into a mainstream product.
Sculpture, Richard Serra
La Philharmonie de Paris, Jean Nouvel.
So you've really got a situation where you are trying to balance the high-culture ideals of the designers concepts with the much more conservative and predictable tastes of the market.