NSA Urges Government Workers to Avoid Public Wi-Fi

Why? VPN is a thing you know?

...which might be because their life focus is something other than being a computer scientist.

Sometimes it seems like we (technological adepts) expect people to be proficient in mechanical engineering because they own a car.

And does the typical person do that?

I assume you're using some uncommon WiFi chipset without binary blob firmware and controlled by well analyzed open source drivers. If you're connecting to networks over anything more recent 802.11n such chipsets are non-existent, AFAIK.

Or perhaps you're using a device where the WiFi component lacks DMA and similar mechanisms to access or twiddle, directly or indirectly, memory or other components; controlled by a well analyzed, open source driver, or maybe a sandboxed driver running under a microkernel. This is more likely, except it's almost certainly not open source and we're basically taking the vendor's word regarding the architecture and correctness of implementation.