Naturally character is better highlighted by what you do that has no tangible reward, and done in the dark, where you think no one will see it. And being nice, and compassionate, and charitable are things that should be done because it is the right thing to do, regardless of reward.

The quote is in the same vein as the original article; the general thrust of the article is that being nice pays dividends, which could be interpreted as being calculating as well, I suppose.

But I don't think that is the intent. I think the intent is the same as my comment - to just highlight the benefits and renewable nature inherent in being nice, not saying that is the reason to be nice.