It's a very effective coping mechanism for dealing with constant problems would be my guess. Here's what GPT 4 has to say on the matter, I think it's pretty hilarious:

"Programmers have such a sunny job, full of rainbows and unicorns, that they've taken to leaving little love notes in the form of sardonic comments within their code. It's their way of whispering sweet nothings to the universe about the sheer joy of tracking down that one pesky, elusive bug at 3 AM, or the pure elation they feel when the system crashes for the hundredth time for no apparent reason. They do it with such grace, wearing a smile that's as bright as their computer screens in a dark room. Indeed, who wouldn't want a slice of that pie?"

It may describe a baseline cynicism about the problem or situation. It's a healthy skepticism, a low-priority thread on the mental backburner.

Sometime later, something triggers it or an idea related to it. You can instantly jump back to it. You think "Hmm, I wonder if I can try X on it..."

Where X is a technique, method, or process you may have done before, but in a different context.

I think there are lots of opportunities to be sardonic in programs! Either literally in comments or figuratively in programmatic structures you use, or at a higher level of project design. Any time the system is in a bad state, appearing like it's heading towards a crash, but you've prepared a clause to catch and diffuse the situation it feels a little sardonic to me.