If you have any questions about why, feel free to raise them with Rinda E. Vas, Corporate Counsel for the American Greetings Corporation.
We're currently trying to figure out exactly how the concepts of Parody and Satire work to protect the sorts of things we do, to better arm ourselves against this kind of crap. Virtually everyone believes that what we did is protected, indeed, I believe that myself - but I'm not going to bet the farm on it until I have a bit more than Internet hearsay to back myself up with.
(CW)TB