The official reason for renaming Gaim to Pidgin is that America Online was unhappy. While this might very well have been the case it is also equally likely that the modern developers realized that the current version of the software was such a pile of crap that they didn't want to detract from what was once considered a rather decent messaging client.
My mind is going. There is no question about it. I can feel it. I'm afraid. Good afternoon, gentlemen.