How do you know that? As an internationally famous author, he has certainly influenced people in some way. It's just incredibly hard to measure how exactly. Arguably, he precisely described the role for artists in society with that quote.

Maybe.

But he did make a fundamental scientific discovery. He proved that snakes and elephants cause Gaussian distribution.

To be fair, the whole quote is about getting people excited to do work not by telling them the actual actions they have to perform, but selling them a dream to long for and work towards.

It could be that his goal was to get people to repeat his quote about building ships. And he did it by selling some dream about being motivational by telling a grand story.

Citation needed.