In my experience, people who shoot themselves in the foot with a magnetized needle are the same people who will shoot themselves in the foot with any other programming technique.

Those who aren't careful enough to only flip the bits they intend to when programming with a magnetized needle are the same types of people who overflow buffers in C.

You can't fix lack of knowledge with a compiler. You can only catch accidental mistakes, but that assumes that the norm is for the person to know what they are doing and a lot of people have only superficial knowledge of the tools they are using.

We already have accident catching tools for magnetized needles. What a magnetic needle doesn't have is a helmet, training wheels and padded walls, which is by design.