The link doesn't entirely clarify what you think "racism" means, though. From what I can tell, you think that the word "racism" is like the word "holocaust"--it refers specifically and only to a particular historical series of events?

(I don't think this is supportable by the usual evidence that people apply for deciding what a definition is.)

Either way, when someone is using the word differently than you think it should be, what do you want to do--discuss their meaning, or their definition? At the very least, don't you want to be clear about which you're doing?