Nobody should poach ideas. But there's nothing wrong with asking, "Hey, if you are that firm on not wanting to write about it, do you mind if I do?" The publisher apparently didn't do that, but still saw fit to "lose respect".

I also don't see what's uncharitable about my reading. I see a rich man looking down on somebody for not being willing to take a risk he won't take himself. What do you claim I'm missing here?