Here is an illustration. “Look, when I compose a symphony, I [do X]; when Beethoven composed a symphony, he [did X].” I swear, that’s an exact quote of something I once heard. One doesn’t know whether to laugh or weep.
[ from A Fallacy Needing A Name ]In more than a decade of higher schooling, from when I arrived at The College of Wooster in 1981, until I returned to the University at Buffalo to defend my doctoral dissertation in 1996, I don't ever recall speaking with anyone in person who labored under any such misapprehension; but if I've seen it on the wing over the Internet once, I've seen it five-score times.
(Much of the time, it's an even worse variety, e.g.: I like [piece of music X] better than I do [piece of music Y]; and anyone with musical taste and sensitive ears will perforce agree with me, because this preference of mine reflects an 'Absolute Aesthetic Ranking'.)
Honestly (and doesn't this tie in neatly) I'm relieved simply to find that another musician is crying out against this.