But yes, once you have the money and the fame, you probably won't be as driven.
Even in that context the threat of poverty still hangs as you're functioning with finite resources which are self-propagating.
It's usually a positive thing if the team can finance their own early growth - with a) a product that generates revenue or b) enough growth to appease investors without cannibalizing the teams creative freedom. Something which provides a runway and capacity to reinvest in a larger bolder vision which might take 2-4yrs.
The ROI of being self-sustainable is the founders can keep the team small, independent, and driven by their larger vision while still keeping them grounded in reality.
Early stage acquisitions have a similar downside as starting within Google, as they have to pursue their larger vision after the massive distraction of being acquired and integrated into a larger firm, which equally kills the necessary culture as pure poverty would.
Same with VC, purely gambling investors money on a long term vision usually leads to an early acquisition or late-game hail-mary focus on revenue - but unlike a small startup they will have much higher revenue requirements, which sideline any big visions
http://dealbook.nytimes.com/2010/06/22/sorkin-elon-musk-of-p...
There are many other sources, and later interviews where he discusses this time of his life.
Apple doesn't hand new product categories 100$ million, they make them prototype repeatedly until they have something worthy of investing full resources in.
If you have $100m in the bank then the only primal motivation for a goal "of creating consumer robot technology by 2020" is articles like this one by BusinessInsider questioning what value has been created.
The arbitrary deadline set at the beginning (2020) could be another motivation, but that could probably be pushed back and the project refinanced because hey innovation is hard.