[Quarrelsome]

Not at all man. The physical environment can be much more malicious than you seem to think.

I've done some software for buses, it's toy in comparison (with planes) but you get issues with noise, power supply, vibration, temperature, light (UV killing a touch screen) and probably lots more i've never encountered. The physical world can be every bit as unpredictable as the virtual one.

[yters]

The major difference is that environmental agents are generally deterministic or stochastic, i.e. obey the law of physics. On the other hand, realms with intelligent agents, such as humans, are inherently unpredictable due to their free will (which is unpredictable by definition).

[Quarrelsome]

You also have the free will of humans messing with the system (in my case, fraud prevention), also consider animals interacting the machinary while someone is not watching. I remember hearing a story about a huntsman spider regularily tripping a sensor for a program that measured the weight of lorries.

The only consistent thing you can state is that all these "real world" issues are to do with hardware whereas yours are more softwarey. However the consideration of such issues is necessary across the board.

[nopassrecover]

I don't know about you but if I was writing a program to fly a plane I'd want to make damn sure I took into account an intelligent malicious agent trying to crash my plane.