Would you leave a safe closed but unlocked? It's no different than leaving a wallet unencrypted.
When the safe is located in your locked house and surrounded by a security fence you might leave it open.
Not quite the same as if the safe has been left on the street is it?
Your house is your computer so obviously your computer (or house in this example) seems to have a lot of open windows, else noone gets in. The safe (encrypted wallet) is last line of defense.
Do you need "a lot" of open windows?
Do you even know how the thief got through the security fences and broke into the house past the alarm?
No one knows at this point and it is not as isolated case it would seem.
Someone has been targeting owners of this brand of safes!
And all the other owners are thinking their safes are secure because they have used an optional password.
What will happen though when their safe is taken and the thief has time to brute force the password.
You will all be claiming it is the safer owners fault once again because he didn't choose a long enough password.
How long does the password need to be. Is the password enforced by the safe security mechanism?
Is the safe manufacturer taking all practical steps to ensure the product they're supplying is fit for the purpose?