There were (almost forgotten now) various semi-valid scientific theories which were precursors to Darwin.
Again, like that special on Einstein and God, this kind of speculation (Darwin doing the theory because he hated God over the death of the daughter) really cheapen his integrity as a scientist - which was in fact a great one.
It is sad to me to see Creationists stoop to attacks on the man himself (the ad hominem) rather than meeting the ideas scientifically.
This cheapens only Creationism, not valid scientific discovery.