"No one wants to hide who they are -- but if you're fighting you have to, to protect the people you care about." And even then, sometimes it isn't enough. Jason still died because of him. Lex figured out who he was when he had those letters sent to him.
You let your family die
You can't save everyone. You can try hard to protect people and still fail, it's a cruel lesson in life but it doesn't mean you can become careless.