I feel people who prefer a more "forgiving" headphone instead of an "unforgiving" headphone have a perfectly valid point. It's about enjoying what you listen to and is why I intend to have several options available, to accommodate the variability in the recordings.
For twelve years I was perfectly satisfied with my vintage Sony Walkman CD and either Bose QC15's or the little in-ear Bose model for my walks. But then I fell off the wagon after I purchased an Oppo 105D to replace a 9 year old DVD player (which broke) and 9 year old BRD player (that was pretty bare bones) and heard what the 105D's headphone amp was capable of, and it was all downhill from there. "Just when I thought I was out..."
As for emotional exhaustion and musical form, I get that at times with my classical music (90% of my listening). At times when I focus too long on my favorite period, (the Late Romantic composers), I'll experience burnout. I fix it with Bach for his clarity, Mozart for his purity, Beethoven for his humanity. If I'm feeling decadent bring on Debussy and Ravel. So many great options; Stravinsky, Vaughn-Williams, Copeland, Schoenberg, Medieval Period stuff, and on and on. Eventually I'll land back with Wagner, Puccini, Bruckner, Strauss and Mahler and start my cycle over.
My classical recordings span a time frame starting in the late 30's to the present day so recorded quality is all over the place and yet unpredictable as to quality by date, so I'm used to variability of recorded quality.
My rock, jazz, and film score music is a different story. I don't listen with a critical ear, it's purely for enjoyment and is always fun, energizing, or relaxing. Most of this year I've been like a 'dog on point' working too hard at listening to all my new gear and that will bring on burn out. But, I also know based on my past experience, in time I'll be over that "new toy" aspect and everything will snap into place for me. I keep notes as I listen to new gear initially, and it's always the case that subtle differences that are difficult to discern the first month or two suddenly become more obvious as I move into a more relaxed mode of listening.
We're all getting too old, it's inevitable. Don't give up and give yourself a break now and then.