I think it is down to what started hundreds of years ago yes, if, as a large group of people you are victims of, well I'm sure you'll agree, a massive amount of wrong doing, is it not understandable to harbour some sort of 'victim mentality' even when the wrong doing is on a much smaller scale. The roots of the wrong doing are in the same place, prejudice and hatred based on race.
Calling people names isn't going to transport us back to those time, I agree, but it has come from those times.
We have developed. We, as a nation, have accepted that racism is abhorent. It is getting a lot better, and this 'kick racism out of football' campaign is just another step towards further development. While the shadows of that ugly past are still looming, we have to do what we can get rid of these too, which is exactly why making such comments is illegal.
When it happens on a football pitch, in front of millions, then an example must be set to show that the law does treat such matters with the severity it requires.