I don't think there are any really, pros of public accounts, besides collab ideas or spreading happiness. They are dangerous, in a way, because you can't tell who's logged on and posted anything. People can post whatever they want, knowing they're covered by a username which tons of people share. It's like if 20 people use the same username "Coder123." Then, lot's of mean messages pop up, and you can't tell which one out of the 20 people posted it.
I don't think you should go on public accounts either. If the mean messages are severe, THT might have to ban all 20 people, even if you did nothing wrong.
Unless there's a way of tracking who did what, I don't think Public Accounts should be allowed.
Should Public Accounts be Allowed?