Whereas the Atlantis CEO seems very into this business for the money and fame, DPR seems more interested in the ideological standpoint of it all (libertarian ideals and all that jazz).
Quotation from Dread Pirate Roberts:
All that being said, my primary motivation is not personal wealth, but making a difference. As corny as it sounds, I just want to look back on my life and know that I did something worthwhile that helped people. It’s fulfilling to me.
Source:
http://www.forbes.com/sites/andygreenberg/2013/04/29/collect...
EDIT: some formatting mistakes