There was a long post a while back, an explanation of sorts. I don't remember it verbatim but more or less, she went away because she was being mistreated, unappreciated and it didn't make her happy any more.
I suspect there was a very vocal minority that took it upon themselves to make the Tag Fairies life miserable and that is what prompted the departure. You haven't been around long but you must have come across the mobs that overcome people like Tsunami's every chance they get. I suspect a few people knew the Tag Fairies secret identity and went out of their way to be mean, because that's just how some people are.
I agree it is very sad, the whole idea of a Tag Fairy brought a little piece of Disney Magic onto the DIS and now its gone. It's just not the same.
