Using a magnetic gate like this has potential to reduce the heat involved in processing large amounts of information, which could lead to much faster chips.
That argument may or may not be true and really begs the relevant question: Did they know about the potential for strong magnetic fields to move ferrous metal components within their locks?
So goes their apparent logic that even if their engineers had considered the potential for a magnetic attack they dismissed it because no magnets were available, at least to the private sector, to accomplish such a bypass.
If you're a frequent reader you're surely well aware of the potential of spin torque transfer memory, or STT-MRAM, and how spin-polarized magnetic currents (and the electrons they love to caress) might hold the potential to revolutionize storage as we know it.