<<<<<A White person who wants his nation to remain White is placed outside the pale of acceptable political debate. He is attacked as an exemplar of total evil. He is punished in any way legally possible, and new ways are being devised all the time.>>>>>>

Just maybe because his racism tends to show a singlemindedness towards destruction of everything and everyone around him? Including himself?
Btw, what contributions to progress are you referring to? Do you mean the development of an industrial system that is poisening and destroying the entire planet? My what a boon to humanity, a little more of that and no one will be alive.