Exactly! I agree with the OP that showing passion for technical subjects is the sign of a productive developer, but I do not agree that the said passion should

Exactly! I agree with the OP that showing passion for technical subjects is the sign of a productive developer, but I do not agree that the said passion should be shown for the exact business problem that the boss is paying her to work on. What the OP seems to say is "Good developers show passion for technology, oh and while you are at it, give me some of your free time".