I have come to the conclusion that some of the tech visionaries recently are actually motivated, on the bottom-most level, by doing Good - in the old-fashioned moral sense.
As far as I can tell, Elon Musk is firmly in this category. Recently I've started to believe that Larry Page and Sergey Brin also belong here. Sure, they have companies and profits and board meetings to worry about, and of course they don't mind having their egos pampered a bit, but their prime motivator appears to be improving the future of humanity on a large scale.
Not everyone is like that, however. In fact, the list is very, very short. I'm only willing to put these three names on it, so far. Most of the others are energized by more mundane reasons, and of course there's also a minority of plain old villains out there.