I've never heard anyone say there is no white heritage to celebrate. I'm sure one moron or another has said many things over the years, but I have spoken to a number of people in various stages of their lives, and this is one opinion I have not come across. The simple fact is, in America, the phrase white pride has been in use, and has had a decidedly negative connotation (at least to me; others will differ, strongly). With most Americans, the use of a word determines its meaning. White pride has been used almost exclusively by people we consider unsavory, unlike black pride, Asian pride, etc.

One of the unfortunate things about popular culture is that it does not discriminate between certain differences between similar things. For example, gangsta rap gives some people an opinion on all rap. The phrase welfare mother generally evokes a negative reaction, but I find it difficult to believe that all mothers on welfare are somehow evil. If someone calls me a hip cat, this is a somewhat antiquated complement, even if it is comparing me to an animal. If they call me a porch monkey, this is an insult, even though I am still being compared to an animal. This is how language works. Some terms, though similar in nature, differed in development and differ in common usage. In short, the American experience influences heavily how words are interpreted by Americans. I cannot speak of other English speaking countries, but that appears to be how things work here.