Not because they are bad, they are actually amazing.
But now if I listen to any song that suffers from the "loudness war" I can immediately notice the horrible garbled mess it is and have to listen to something else.
When I used headsets I never an issue with shit tier mastering :(
And now I cannot go back, because everything would sound like shit now.
I was listening to the display model solo's at some store the other month for kicks and all my music couldn't cut through the shit that was loose and overpowered bass. Not to mention the sloppy mids and non-existent trebles.