This staffer's opinion is not reflected by any actual policy, public or private, of Facebook to snub Google and Android, but it goes to show you that things aren't so warm and fuzzy between the two companies.
Several blogs are supposing some of the bitterness has to do with Google's support of Facebook competitors such as MySpace, Bebo, and others. Facebook has prevented Google's FriendConnect service from working within Google. Take everything together, and there could be some genuine animosity, but that's speculation.
In the end, Facebook will really only hurt itself if it chooses to ignore Android. It may be a brand new mobile platform with only a handful of users, but it's sure to grow. Given the highly powerful services that Android can connect with, it would be a shame for one of the more important social networking tools to un-invite itself from the party.