If you have $100m in the bank then the only primal motivation for a goal "of creating consumer robot technology by 2020" is articles like this one by BusinessInsider questioning what value has been created.
The arbitrary deadline set at the beginning (2020) could be another motivation, but that could probably be pushed back and the project refinanced because hey innovation is hard.
But yes, once you have the money and the fame, you probably won't be as driven.
Even in that context the threat of poverty still hangs as you're functioning with finite resources which are self-propagating.
It's usually a positive thing if the team can finance their own early growth - with a) a product that generates revenue or b) enough growth to appease investors without cannibalizing the teams creative freedom. Something which provides a runway and capacity to reinvest in a larger bolder vision which might take 2-4yrs.
The ROI of being self-sustainable is the founders can keep the team small, independent, and driven by their larger vision while still keeping them grounded in reality.
Early stage acquisitions have a similar downside as starting within Google, as they have to pursue their larger vision after the massive distraction of being acquired and integrated into a larger firm, which equally kills the necessary culture as pure poverty would.
Same with VC, purely gambling investors money on a long term vision usually leads to an early acquisition or late-game hail-mary focus on revenue - but unlike a small startup they will have much higher revenue requirements, which sideline any big visions
http://dealbook.nytimes.com/2010/06/22/sorkin-elon-musk-of-p...
There are many other sources, and later interviews where he discusses this time of his life.
Apple doesn't hand new product categories 100$ million, they make them prototype repeatedly until they have something worthy of investing full resources in.
Nobody else is like Apple, except Apple.
http://www.bhorowitz.com/ones_and_twos
Larry Page is a One, Andy Rubin is a One, Eric Schmidt was a Two, and Sundar Pichai is a Two. I think Jonathan Rosenberg is a Functional One for product (he left when Larry became CEO, before I had a good sense of Google internal politics, and seems to have come back now that Sundar is CEO of Google). Marissa Mayer is a One. Make of that what you will - IMHO it explains much of the executive changeover in a couple different Silicon Valley tech companies over the last couple years.
their current investments are in wifi hardware, social connectivity, and brain-based neural networks. (1)
Going from buying 6 very specific hardware robotics companies to a diverse base hardware incubator raising money with LPs is a different flavor than being "the" robotics guy which was clearly Larrys vision for him
(1) https://www.crunchbase.com/organization/playground-global/in...
Andy is a visionary.
He left Apple to found Danger which was one of the "genesis" products that led to the smartphone era. (1)
He made the next huge leap with Android and almost failed until Google showed up to help him fully execute his vision under their stewardship.
After Android became a very mature business in its own right what to do with the visionary founder?
The article states that "Page is interested in robots" - can you imagine if Larry Page came to you and said "Hey how about you literally build robots all day. You could be Tony Stark and here's $100m to get you started. We'll change the world!"
It's a hard to turn down offer, Rubin accepted and tried to recapture the magic pursuing somebody else's vision.
But it's damn tough to be a founder / visionary under somebody else's thumb, especially when you're set for life financially.
That's a story that never works out, but is played out again and again in technical acquisitions as big organizations attempt to find a place for founders.
(1) https://en.wikipedia.org/wiki/Danger_(company)
(2) https://en.wikipedia.org/wiki/List_of_mergers_and_acquisitio...