I don't have an issue with every "error" on that page and I have no problem with style guidelines for writing, but the problem comes when the prescriptivists think that logic is on their side when they opine on subjective stylistic and dialectic issues. "Ice tea" is a perfect example. The author of that site argues that "iced tea is not literally made of ice, it simply is 'iced': has ice put into it.". Apparently he is unaware of English's enormous fondness for attributive nouns. By his reasoning, we should all be saying "appled pie", or "apple-infused pie", or something crazy like that.

I also have a more general problem with prescriptivism because frequently it is used to justify a certain type of racist and classist thought.