People have their Bitcoins stolen all the time. If someone can't keep a forum password secure, chances are he'll lose other data too. Even worse, phishing sites may start abusing this by convincing people to enter their private key. People are already entering their password on fake Bitcointalk (phishing) sites!

I've never seen any other forum where so many users lose access to their account. It's your own responsibility to keep your computer secure, Admins are already overloaded in work, and I don't think they want to add more features to the forum just for people who can't keep their password secure. Account recovery doesn't have a high priority.