>The irony is unreal. Where's the hardware?

It's the rotary phone and the raspberry pi, of course. Don't gatekeep.

The fact that microcontrollers are so cheap now means for most (but, sure, not all) applications they're strictly superior in every way compared to e.g. 555 timers and LM386 amplifiers, or whatever. This is because, critically, you can debug and reprogram a micro. To do the equivalent with a 555 timer means, at minimum, de-soldering a bunch of components and probably poking around with a logic analyzer or an oscilloscope.

What's more, you can get a full tcp/ip stack in a surprisingly small and low-power package these days. No need to futz with analog telemetry, or even SPI/I2C unless you really need to.

The "hack" in TFHackathon is altering the function of a phone. Who cares if they used a ras pi to do it vs something else? In what possible way does that diminish their feat?