It's not very surprising. The computers are relatively basic by desktop standards and the time taken to develop a system securely means that many "obvious" thin

It's not very surprising. The computers are relatively basic by desktop standards and the time taken to develop a system securely means that many "obvious" things as seen from the armchair don't exist irl. Also, like most engineers, you don't necessarily add systems for every conceivable thing that could go wrong. If you think about how many times this has happened against the millions of plane-miles travelled, you can see why it wouldn't necessarily have been high on the list.