I wouldn't go so far to say that good sound is in the ears of the beholder. This sort of statement is applicable for things like wines where the only comparisons available are relative to other wines.

In audio we have the opportunity to make an absolute comparison of reproduced sound to live sound. If you believe that the best sound is accurate sound (this assumption is, I admit, subject to debate), you can't help but be ruffled by this meddling with the tone controls.