The person who originated the practice and created the first "brainwallet" site did exactly what you're doing: insisted that it was secure, and insisted that people who lost their funds deserved it. Are you also doing what he did? stealing the funds of the deserving victims yourself?

Eventually taking the weak brainwallets he talked people into creating wasn't enough: He lost his bitcoin (I think via gambling but maybe an exchange hack), whined he was broke for a while, and whined that not many people were making hackable brainwallets, then added a more explicit vulnerability to the site. He vanished after it was caught.