It's not about them saying "Windows Vista curropts iPod", it is about them saying "Do not use Vista, if u have an iPod".
What the user uses as the OS is his choice. Apple knows that iPod has a large market share, out of which, 90% are Windows users, so by coming up with stetement like these they can easily blame MS for their own flaws. Remember the case of iPods with Windows virus in it, they did not accepted their mistake, they said, it's a the flaw of Windows that it is not secure, not the flaw of Apple to bundle iPods with Virus
