She and the majority of investors that write about founders have the "company purpose" thing backwards.

Almost all the CEO/Founders that speak of deep purpose have arrived via a strong path of revisionist history.

I'm the founder of two large tech companies and the way that it goes is that most founders have an idea that is driven by some vague desire to solve something or test something. What ends up happening is that as the idea grows you are forced to recruit people and money. As you are forced to tell the story of your company, you workshop the emotional parts to become more effective in resonating with your audience. By the time you are raising even an "A round" your story is extremely polished and emotionally moving.

I must add this is almost never done with manipulative intent or dishonesty. The mere act of becoming an orbit as the company grows demands persuasion at ever level.

The story of purpose is heightened by the success, it does not create it.