You can say this about any field. A ditch digger loses "intrinsic motivation" and chooses to not dig a ditch. The ditch digger can't do their job because of burnout.
But somehow it is different in software development?
I'd argue that yes, it is different in software development.
The nature of ditch digging is such that given enough effort, it's probably still possible to dig a ditch. It doesn't mean you'll be motivated to dig the ditch, it doesn't mean it won't be ridiculously hard to dig the ditch, but barring seriously physical issues preventing you from making progress, digging a ditch is mechanical and doesn't really involve a serious need for critical thinking.
When you burn out as a software dev (and probably other fields that involve serious mental investment), it doesn't matter how much you try, there's a good chance you'll just fail.
I do agree that software development is not the only field that can be seriously impacted by burnout, but the degree of impact seems to be highest in fields involving knowledge work.
Hilariously I'm that person who was forced to dig ditches a few times and experienced a mild case of burnout as developer.
In both cases the performance was similar. With earthworks I simply didn't give a damn about the job, so just pecked the ground unenthusiastically. With burnout it was as if petard went off, but instead of earbuzz you get numb to planning, focusing and executing. I actually felt bad about it, but doubt you'd see much behaviour difference from the outside.
So I'd wager the lack of motivation is a serious handicap in both cases. Sure, "anyone can dig a ditch" but I dare you try doing it for a day if you are not into it. Similarly I was already an experienced developer at the point of burnout, and the job at hand wasn't challenging at all.
I don't think you understand the previous comment. Often, with burnout, motivation is not necessarily the issue. You try, or believe that you're trying, your absolute best but everything is falling down around you.
It's not just about motivation, it is just that your perceived ability to execute (going through the motions) and actual ability are completely at odds and you eventually lose all confidence in yourself to continue.
It's not motivation for the job, it's belief in your own abilities / capabilities that erodes your motivation.
Perhaps every case is different, but I hardly can imagine how one can remain motivated in a burnt out condition. It's not like the lack of motivation is the cause here. It's more like the lasting effect that holds your capabilities down.
E.g. I still could read the assignment, understand the problem, even estimate how long it could take the former me to complete. Then continue wasting time in front of the screen, sometimes dabbing here or there, at 1/20th or so of normal work pace. The confidence sure suffers badly, but really it was down to complete lack of will to do anything.
There was a grandsibling comment that you can actually force healthy person to dig ditches and do other menial labor no matter what. This is a problem well studied by prisons and armies of the world over millennia. Thing is, whipping isn't usually tried with burnt out devs, who knows it could have worked. It's not like your IQ drops 50 points or something. USSR and China had a fair experience of forced intellectual prison labor, and things were getting done.
You can whip a tired ditch-digger until they dig more.
You can't whip a tired programmer until they write working code. You'll only get broken code.
A good analogy might be to the division between rank-and-file soldiers in the military, and military officers. You don't need to think to shoot a gun. You do need to think to decide where to send people to shoot their guns.
I think it's all about creativity. When you burn out, your creativity dries up. Most of programming (and generally thinking) is done by your subconscious, and when it says 'I've had enough of this, I'm not helping any more', you are SOL, no amount of willpower will help with that. That's why digging ditches is different.
an emotionally exhausted ditch digger can still use their arms and legs without impediment. an emotionally exhausted programmer cannot focus mentally and cannot write code at all.
But somehow it is different in software development?