Who decides what is 'well-adjusted' or 'productive'? What's a positive role model?
Well, you're right in that those terms aren't necessarily well-defined.
For a start, I'll say that "well-adjusted and productive" when describing a person= "positive" when describing a role model. I only used the former phrase because I didn't want to sound repetitive.
Then, I could start by saying that I mean non-criminal at the least, financially sound would perhaps be another "positive" step. I'm sure I could think of others--some surely would be arguable as to whether they are generally positives.
In the sense that society defines the law, I guess that means that society defines what is "positive" to some degree. Financial soundness seems to be less lauded by today's society, but I would lump it under behavior types I consider "positive."
However, the point I was trying to make was more that I'm not surprised that giving people experiences that show how what might be typified as "good" actions lead to "good" results makes them more likely to do "good" things. I expect that people's experiences affect their behavior. I would expect it to work with books, perhaps not as effectively as with people. It's good, in my opinion, that people reading about ethical behavior (whatever that amounts to) act more ethically.