It is anecdata, but I can confirm this is the case for my code.
I tend to focus more on documenting the surprising code paths, not the mundane. And when my code needs to do something special because some other component (library, hardware, API) has issues, there's usually some colourful language describing the sad state of the world outside my control.
Also any mature, well maintained code will have found a lot more of those truly ‘wtf’ bugs and edge cases, which often involve same colourful language when we finally figure them out.
I tend to focus more on documenting the surprising code paths, not the mundane. And when my code needs to do something special because some other component (library, hardware, API) has issues, there's usually some colourful language describing the sad state of the world outside my control.