The title has some merit to it if you actually think about it. Just imagine, that these companies are employing terrible security, yet they're hosting millions of pounds worth of Bitcoin, and sometimes more. Yet, we expect the average user to have good security, when we know that people are generally quite lazy.

How many users are verifying the signature of their wallet, how many are checking the software they're using. I bet they see it as open source, and just blindly trust it. Then, you've got people hosting their wallets on compromised machines or just poorly implemented security like weak passwords or sharing their credentials with people they trust.

I've said this before, but I don't think being responsible for your own security actually appeals to everyone, and that's fine. Hence, why banks will likely always be used. Since, if you are someone that doesn't know anything about computers or security, trying to secure your life savings on a computer probably isn't the best idea.