This resonates with me. That's the kind of drive that results in great output. Buying it just for that.
I've been approached by publishers several times throughout my career. Each time the process was similar: they had an idea, I had an idea, we tried to come to common ground, and then the deal fell through because we couldn't find any. E.g. I didn't want to write a Java book aimed at 14 year olds. They didn't want me to write about classloaders (or whatever niche subject I was diving into at the time).
Would love to learn how people find (non-empty) intersections of their passions & what readers want.