[Elenna]

Some security situations might warrant the admins issuing new passwords, instead of waiting for members to log into their account and change it (for example, hacked database where their old passwords might be dug up from somewhere).

If passwords were compromised, the hacker (or password stealer, etc) could simply log into the site, choose a new password that the valid member wouldn't know, and then have full access to their account and your forum.