I recently had a conversation with a writer I admire and respect. They had a book on a topic I can't bring myself to touch.
Because I knew this writer I said as much.
I did so because I didn't want them to think it was a pass on the book or them.
On the other hand, writers who send queries, writers I don't know, just hear no.
I'm not able, and don't want, to engage with them about why I will never take on a book on this topic, or will not take this book now.
Some things I don't want to read about.
Some things I simply can't.
And often, the more heartfelt the book, the more likely you'll hit this kind of snag with at least one agent.
I know your first response to a pass is to think "I suck. My book sucks. This writing thing sucks."
But your second response should be "Wait, I read about this on the SharkForBrains blog. Maybe she's just not up for fruit memoirs after she was horribly disfigured in a strawberry explosion last year."
Every agent has a Fruit loophole of one kind of another.
Most of us will never tell you what they are.
You just have to know they are there.