Last time I checked, Mt. Gox was open for registration, so this is not about being able to trade or not. This is about people making the staff at Mt. Gox waste time just so they can get to keep their username, and making the people who have actual funds lost in the system wait even longer for their accounts.
No that's not what it's about. It's about me wanting to keep my @#$@ email address and not have to keep track of some new email address I'll never use on anything else but Mt. Gox.
Zero balance unused accounts should have been auto recovered by script when a recovery request was made (It forces you to change to a secure password anyway).
They could have added that script in like 2 minutes or less, doing so would have immensely reduced their workload.