I understand that in the real world people are used to listening to their rather live rooms and it might sound strange in a treated room. But once your brain tunes into the sound emanating from the speakers you start hearing the room the music was created in, or at least the ambient space that was created in the mix.
Sure, live music occurs in an acoustic space and that's an important part of the original sound. But a good recording captures that sound and that's what I want to hear. An untreated, live room distorts the sound in the recording by adding sound that wasn't part of the original performance. No different than noise.
A room needs both diffusion and absorption for different reasons. But the net effect of good treatment is reducing the sound of the room and allowing you to hear the recording without added noise, which is what reflections are. Noise that wasn't contained in the original recording.
A good recording studio isn't anechoic but rather a place where music sound fabulous. Spend some time in one and see.
I hate listening on headphones. My point is that people who do like them don't complain about the absence of room sound. They like hearing the actual sound of the recording, not the sound of the room they're in.