I think you have to put that initiative into context. It makes sense so be a militant Darwinist in America -and I would probably be one of them-, while it wouldn't in France (for instance).
In Europe, an overwhelming majority of people knows that the evolutionary theory is correct, and that what the Bible says should not be taught alongside in schools.
While in the USA, you have a very strong creationist lobby, especially with their so-called "intelligent design".
Political militantism makes only sense where your ideas are threatened, where you have a fight to carry through.
The contribution of Darwin to modern science is huge, and his ideas were far more decisive and influential than most of the other scientists quoted there (Newton, Maxwell or Tesla). There's no possible comparison about that, it's a no-brainer.
So basically, I'd say the wish to make a "Darwin's day", is not that stupid or irrelevant.