Have to disagree. Have you compared hd600 to for example Stealth? You can EQ hd600 as much as you can, but it won't sound the same.An HD600 + a $200 dac/amp is all anybody actually needs to enjoy music . This isn’t about music. It’s about endless gear chasing and tweaking to chase an imaginary state of perfection that lasts until the next new product is announced. I’m not immune to this either….
Clarity, soundstage/spatial effects separation of the notes is top notch on the Stealth. Of course you can still enjoy hd600 (actually it's my second pair of headphones and I really like them) but it's not in the same league as Stealth (both objectively and subjectively)
Another matter is if somebody wants to spend that amount of money for headphones - don't get me wrong it's expensive, but some people see value and are willing to spend their own money, nothing wrong with that.
Of course there is a lot of gear in our hobby that doesn't perform (objectively) on par with it's asking price but headphones from Dan Clark are the exception.