I just watched a film of Steven Levitt (co-author of Freakonomics) giving a speech at a charity fundraiser. He explains his personal connection to the organization - he adopted his daughters from China, and this is a charity that aims to improve Chinese orphanages.
After praising the charity's mission, Levitt asks, "Does it work? It sounds great, it's a nice story, but how do we know it really works?" He goes on to explain he'll be conducting a rigorous academic study of the agency's effectiveness.
I can imagine some people's reactions to that. "Jeez, these economists. How can he be so cold? How can he analyze the effectiveness of comforting orphan babies? Can't he just see that it's a good cause and let it be, especially when it concerns his own child?"
But I'm guessing he's doing this study because the topic is so close to his heart. Yes, it's great that some kids out there are getting a better life. But are we doing the best we can? What if there's a better way to help them? If it were his daughter still in an orphanage, Levitt wouldn't just want well-intentioned help for her. He would want the best help for her. And that's exactly why research matters.
For another take on this, see Holden Karnofsky's "Reason versus emotion."