The fact that you can express such difficult, contemporary and necessary ideas in such a coherent and progressive way and in a language which is not your first is hugely impressive. These are highly current issues and I suspect my contribution will be less cohesive than yours. I will try anyway .
I agree with much of what you say. I agree that the postmodern trend of relativising everything is lazy, empty and ultimately leads nowhere. It is so much easier to criticise, deconstruct, analyse, to see the values of things only in their own terms than it is to build, create and make things happen. The trend towards everything being of equal value ultimately takes the value out of everything. You remind us in your piece that postmodernism began with the "arts", generalised to culture, politics, science and almost every other field. Also, you remind us that that perfumery is an often viewed as art. This makes these concepts incredibily relevant to our discourse here.
You write "I personally am not very fond of this new trend in fragrances, where it seems that the concept is more important than the execution." This has deep resonance for me in many aspects of current hegemonic culture, not least perfumery where this idea greatly informs my taste. The parallels with modern art, music (both popular and "art"), politics (spin anyone?) and other areas are plain to see. Indeed, where is the timelessness? Perhaps it doesn't matter any more because it smells like an old man? For me, the only transcendence humans can attain is that feeling of gravitas, learnedness and timelessness. Sometimes we create things which "feel" like they are carved from solid rock. This is how I define value.
"Beauty is an inter-subjective concept, and not at all an empty one." I agree with this entirely. I believe that it is socially and culturally defined. People co-exist simultaneously in many cultures and societies. I am informed by my family, friends, profession, hobbies, education, national physical and political environment, my city, my locality and many more specific and random factors. My taste and concept of beauty starts as a product of all of these and is adjusted by my endeavours and changes in all of these factors.
The issue of personal taste against appreciation of beauty is also interesting. I think that it is useful to be able to appreciate that, for example, a fragrance will have the "timelessness" quality for someone else but that it doesn't resonate for me. Dior homme falls into this catagory for me.
My solution to the relativism issue is basically to come back to a modernist, constructivist approach. I consider myself a neo-modernist (a post post-modernist modernist ???). In my view, realtivism relitivises itself out of existence as if it was hit by a conceptual self imploding neutron bomb and we are left with only what we have built. Perfumery is a craft of combining fragrant materials. Sometimes this is done with great depth of experience, attention and little restriction of cost. Sometimes it is done with only commercial concerns in mind. There is a much greater chance of attaining "timeless value" in the former case. The products of this craft may or may not be considered "art" due to the zeitgeist.