Highly speculative thought.
I don't often get angry/upset/exasperated with the coding or math that I do, but today I've gotten royally pissed at some Java project of mine. Here's a guess at a possible mechanism.
The more human-like a system feels, the easier it is to anthropomorphize and get angry at. When dealing with my code today, it has felt less like the world of being able to reason carefully over a deterministic system, and more like dealing with an unpredictable possibly hostile agent. Mayhaps part of my brain pattern matches that behaviour to something inteligent -> something human -> apply anger strategy.
In light of reading through Raemon's shortform feed, I'm making my own. Here will be smaller ideas that are on my mind.