I personally feel like the reason Tooter was not used that much is that it was too restrictive, you could only use it in-game, and on your phone, which is frankly not enough to hook an audience to something.
I feel like that with proper work, and a accessible web client, it could probably become a lot more used, since you can simply check out any toots and reply to them without having to be on the server, so the bar for entry is a lot lower.
Hell, if we pull of a web client, an actual app may not be that far off.