Some famous reviewers have atrocious listening rooms!

Another issue is when old ears are used to evaluate music without a disclaimer.

Another issue is when young ears are used to evaluate music without a disclaimer.

(In other words both has "issue" and a age could be interesting to have declared.)

I recall an article where Fremer talked about the incoming AC service in his building as being compromised as it was literally hanging off the building. Repairs were done and he claimed his system sounded much better. I remember thinking "Does that negate all the reviews he did before the repair?

If you’re in the business of reviewing gear, listening in the same environment time after time and having a baseline is probably most important. Live sound guys who are hired to run sound in churches, clubs, concert halls talk about “ knowing the room.”  I suspect seasoned reviewers are the same, consciously or not. 

@jjss49 You can see the full presentation on YouTube - “Reviewing Loudspeakers: Mesurements and Listening Tests”. The tests were conducted at Harmon, where factors such as volume were controlled. I don’t recall much detail in how they trained the Trained Listeners.

Few of us have proper rooms but most of us strive to achieve a better sound after understanding their limitations. The good thing is that it can work both ways, with or without treatments, but either way it takes time and experience to get most of it right. It's nice to have a well treated room, some can achieve even better results with measurements too, but still an untreated one could work just fine. For example, my room is small, peculiar and untreated with tall speakers and a big amplifier, that would translate in a disaster or wrong approach for many, but after some hard work i have managed to make it vanish, so it can be done. Unfortunately there are several variables that affect sound reproduction in a system so judging by pictures alone we cannot get the whole picture but an idea.