Most of the ranting I've done here applies mostly to queries for novels.
The biggest reason I turn down interesting non-fiction queries is platform-lack thereof
If you want to write non-fiction (excluding memoir) you must have platform.
You need to tell me this in your query letter.
If your idea is anything less than 100% ohmygod, I must have that (and figure you're in that category just for safety sake) I won't write back and ask "what's your platform."
The reason is I don't want to get involved in a long drawn out discussion of what is/isn't platform and why this idea is so great you don't need one.
Experience taught me that the less likely I am to take or like the book, the longer the email exchange.
You can understand then why I don't even want to start.