Earlier quoted context omitted.
Regardless of whether or not it accurately explains the term’s origin or true meaning, the Venn diagram seems to present the more compelling idea.
I disagree. The Venn diagram version positions satisfaction as contingent on things you cannot possibly control ("That Which the World Needs" and "That Which You Can be Paid For"). This is a recipe for perpetual unhappiness and dissatisfaction for most.
The question, then, is how do you balance: 1) making enough money for food and shelter with 2) your intrinsic values? Also, will making more than enough money help you further achieve your values?
The diagram presents a framework to find an optimal solution. "That which you love" is a function of your intrinsic values. The other 3 circles will help you efficiently convert your time into money to support what you love. I guess the better diagram would somehow convey the fact that, ultimately, what really matters is that which you love.