If you don't do what you love you won't be good at it, hence you are reducing your contribution to society. Of course we have a moral obligation to others because we are social animals, but that doesn't mean that the only way to help is doing humanitarian work.
What's generally morally condemnable is being lazy, not contributing.
Besides, regarding his citation of Musk, that guy (and his team to boot) is only doing it because he is really passionate about it. Being something extremely relevant to human progress that no other private company is doing to that extent might help fuel the passion, but could not for the love of him trigger it had he not loved the field.
But what decides what we love? Is there some innate sense to each of us that governs what we're able to be passionate about? Or is this socially-constructed, as a result of the environment and culture we live in?
What's generally morally condemnable is being lazy, not contributing.