1. Hearing merely begins at the ears. It is a brain process. The sustained interest older audiophiles have devoted to the hobby results in knowledge and expertise that ENHANCES the brain process of hearing. This fact more than makes up for older listeners' diminished frequency perception. I suspect this is what Elizabeth was alluding to when she said that there's an important difference between hearing and listening.
2. Perhaps older audiophiles would be at a significant disadvantage if technical listening were reducible to hearing frequency response. Thankfully, it is not. In addition to hearing frequency response, there is also hearing transient response, harmonic accuracy, resolution, soundstaging, PRaT, dynamics, coherence, etc.. Diminished high frequency perception might have some effect on the perception of each of those characteristics, but NONE of them is reducible to frequency response.
3. In addition to the TECHNICAL characteristics just mentioned, the appreciation of music is most importantly a matter of listening to its AESTHETIC characteristics: its beauty, emotion, interpretation, authenticity, imagery, etc.. The appreciation of those aesthetic characteristics is largely learned through experience. That would give older listeners another potential advantage over younger ones.
IMO, frequency response is one of the most over-valued characteristics among a particular segment of audiophiles. Likewise for frequency perception.
Bryon