My tone is not intended imply necessity -- more that several of those figures ARE in fact parents. Darwin and Dickens both had 10 (10!!!) kids. I'm not interested in a discussion of good vs bad vs absent parents, I was trying to point out the kids and parenting are a significant time chunk.
I'm sure that we could go through the list of "creatives" here and enumerate the progeny for each one. In the way that the viz breaks down various other categories around "creative work", I jokingly suggested that a parenting vector is also warranted (though obviously impossible to produce) given that many of these figures had kids and in significant numbers.
I would suggest watching any topic you find interesting at pyvideo: http://pyvideo.org/ These are recordings from most of the major Python conferences around the world