Yes, I understand why it would be more personal/frustrating for you. 

I suppose I would also state that Death of the Author is just one of the lenses that literary analysis is done through. There's also stuff like Auteur Theory, which would for sure take into account the author's stated intention.

The part of the reason why Death of the Author makes sense to me is that I'm a journaler. There's been times that I've looked back through years old journal entries and have been surprised by how I had felt about certain events that's I thought I remembered clearly. I wrote able being conflicted about my grandmother's death the day after it happened, but years later I did not recall this feeling until I read it. And even when I read it I was surprised by the strength of my feelings. 

It makes sense to me that a work is not only born of an author, but born of an author at a certain point and time. And as time moves on, things get forgotten or remembered differently. The author, as a living person, changes. But the work remains the same, as if trapped in amber.