It's simply that I only have a single standard of judging music and it does not change irrespective to what music I am listening to and I stick to the infallibility of my own fantasy way of judging music. I may not have the same talent as a famous composer but god damn it I'm going to match them on the same rigid ideological zeal that my way is he best way and damn everyone else.
Perhaps because I used to be an amateur songwriter and when I listened to music, I made a conscious effort to dissect what I like about a piece of music and what I dislike about that piece as a way of creating my own personal style and principle that I adhere to when writing songs. My personal criterion of judging music was developed as a tool to developed my own personal identifiable style that unite my own songariting despite whatever genre I tackle. The fact that i no longer write songs but the ideological zeal of my standard of music is intrinsic to me as the personal style of every songwriter and composer.
So I don't think it's necessary lack of understanding (I admit there are some music I don't understand but I don't think it's the case all of the time. I believe that my essay on Messiaen demonstrated some degree of understanding on what he was trying to do and what he was trying to express. I just didn't like it despite of it as it conflict my own personal ideology
Understanding what the musician is trying to do is simply irrelevant and not a factor to me enjoying listening to the work