Do you agree with this page?

Sure. It's a flowery version of the Golden Rule. It just says you do what is right because it is right, not because you expect people to automatically respond in kind. Your motivation has to be love, because if it's the expectation of reward, you'll burn out. Quid pro quo is childish and self defeating. You have to believe in the big picture and work toward it, even if it looks hopeless. And the engine for all this is love, despite the obstacles.