That's not an example of bad design though. It's the most elegant design possible on a tool designed for one task. In ordinary use, the design is perfectly safe because nobody has any motive to do what you'd have to do for it to be dangerous and everyone is trained to avoid that danger.
I mean, you might as well say a chainsaw was a bad design because it has moving parts that you could hurt yourself with. One does not follow on from the other.