Is "underground" the sub-culture of "cool"?
To be underground, you had to do what you believed in, at the potential expense of passing on any new temptations or riches.
The lure of the underground is that if you could avoid jumping upon a capitalist bandwagon during your entire adult life, and stick to your guns forever (or for as long as you can creatively defend not doing so), you would have proven a methodology for happiness by exemplifying singularity for your peers and colleagues.