Couldn't disagree strongly enough that one needs to perform it to have that opinion. Maybe I could agree that one need be able to read a score to have that opinion. After you've listened to enough of a composer's music, the period in which it was composed, when in his career it was composed and what he/she has written on their music you can get a very good idea what a good interpretation is and what a poor one is.
Otherwise everything just turns into this convivial, "it's all wonderful to you!"
We have to have some metrics by what great music and interpretation is. I'm surprised this is news to you given the rather broad blanket statements you make on dismissing performances.
It’s not news to me and my point is everything we think
is a question of whether we like it or not and also remember, I never dismissed Arditti’s performances, I just disagreed that they’re better than the Schoenberg Quartet. Thankfully, Schoenberg has been served well by many great quartets through the years that there’s enough differentiation between all the recorded performances that we can choose which one to listen to.