i went to a qualcomm presentation at CES a decade ago where they demoed surround sound with basic cheap stereo cans and it was impressive as hell. i was always surprised it never seemed to take off as a general thing.
There are dozens of ostensibly high quality brands selling 500 dollar headphones with drastically different audio quality. The audiophile community would often have you believe that all such headphones are junk and a random small brand has the best headphones of all.
At least tvs have color accuracy/size/price. Headphones are not measured with any clear metric of quality as far as I've seen..
It's hard to compare when a person goes into one shop and hears an action movie, but in another one he hears a concert/symphony on a different speaker/headset.
So it ends up that most places just post the measurement curves and expect you to learn how to read and compare them yourselves.
Although, as far as I understand, headphones are both quite simple in engineering and complex with the task they try to handle.
Every person's audio perception is unique and depends on unique anatomy and unique experience (brain calculations). So it is quite difficult to normalize every data we can measure.
Still, some are trying to do it. E.g.
http://rtings.com/ - authors develop their methodology to take into account all relevant measurements, and explain their function
http://diyaudioheaven.wordpress.com/ - author does a measurement based subjective analysis of overall audio experience. Sometimes directly comparing rivals in relevant aspects.
https://www.reddit.com/r/oratory1990 - based on research from Harman R&D, measure and develops equalisation parameters for popular headphones, as well as, their weighted score (deviation from target)
The research is quite interesting in itself when addressing you statement, because it develops a statistical model of preference for audio reproduction by average human. Of course, it is not a silver bullet equal for all but many agree they enjoy headphones with "target" frequency response more.
the root of the issue is audio is highly subjective so what sounds good for you may sound awful for me. Confound that with other variables such as amps and dacs (tubes, class A, "warm" vs "cold") and it's a total mess.
Second headphones ARE measured with a clear metric, you have frequency response graphs and distortion graphs which paint a objective picture about how the headphones sound.