I guess at some point (purely enechoic) my argument falls away but...
Actually I think anechoic example makes your point even stronger, Mike.
I have experimented with anechoic chambers a few times, and found them to be excellent for music listening. Every sonic aspect is drastically improved when the echo is eliminated. The brain adjusts to the uncomfortable silence after a few minutes, but playing music relieves the discomfort immediately and the reverb on the recording makes you feel like you are really there. Tonal detail and bass clarity are vastly improved when comb filtering and modes are gone. Dynamics are vastly improved, because there is no background noise and you can turn the volume way down, leaving much more headroom before SPL or amp distortion pains. In a small anechoic space there is some cabin gain too, which makes small sealed 2ways equivalent to floorstanding 3 ways in a real room.
But it does get a little hot in there...
I liked it so much I'm building a 6' dodecahedron shaped chamber for music listening, meditation, brainwave training, etc.