That's just a linguistic peculiarity, I suppose. If you're referring to a group (like the entirety of AnimeGAF), depending on your perspective it can be singular if you view it as one entity or plural if you view it as the individuals that comprise the group. By saying "we" instead of "I", I was giving credit to the thread rather than myself.
That's actually one of the differences between British and American English--when referring to the actions of corporations and organizations, the British would tend to say, for example, "Nintendo are" while Americans would tend to say "Nintendo is".