The Eames Lounge, for the man who is Different.  

Eames chair is versatile
As aforementioned,the Eames chair looks more at home in a wider variety of settings than many other mid century pieces,hence its attribute to classic design.A Jacobsen egg chair is cool,as is the Papa Bear chair,(but,at $12K who can afford that, anyhow?)so when we think of classic American design ,we think of the Eames 670.Maybe in the same sense as Levis 501's for their classic,enduring appeal.Sure there's knockoffs for everything, hence Plycraft can have an appeal.Ugh,those wood plugs,though.

Proxy
Most people here have already mentioned the "proxy-for-taste" argument. You either buy the chair because you 'get it'. Or you buy the chair because you want to appear as tho you 'get it'.
I don't even think that's necessarily a bad thing. I love Rachmaninov, but I don't need to understand every complexity behind the music to enjoy it. (although I might not enjoy it *as much* as someone who understands the complexity.)
Same with the Eames. I deeply enjoy the chair - beyond just sitting it in. I have read books on it, disassembed it, repaired it, researched it etc. And yes, it's everywhere. That doesn't diminish my enjoyment of my chair. I think of it sort of like seeing an old friend.
Icons are icons. 1006 Navy Chair, Eames Lounge, Barcelona, BMW3, VW Beetle, Mac, Rolex etc. They rise to the surface because of their quality but also due to some intangible timelessness of their designs. I expect in 50 years the Eames chair will still be selling.