There's no demand because they made the process more or less impossible for developers to ever get to to the point where they take the PE exam.
First, the candidate has to pass one of the Fundamentals of Engineering exam to become an engineer-in-training. Except, whoops, there isn't a software specific FE; the most relevant one is the EE/Comp. E. exam. Take a look at the list of topics: https://ncees.org/wp-content/uploads/FE-Ele-CBT-specs.pdf Most developers aren't going to pass that even with a CS degree.
Secondly, you need 4-8 years of supervision by a licensed engineer. Again, whoops, there are barely any software developers with a PE license, so who would they get to supervise them?
Frankly, the situation was so absurd that one has to suspect that NCEES didn't want to certify software developers as PEs.
Provably correct software development is too slow and specialized to be economically feasible. Even formal correctness is not enough, you also need to defend against unpredictable hardware faults. No traditional engineering discipline needs to do this.
https://ncees.org/ncees-discontinuing-pe-software-engineerin...
It was only ever administered 6 times.
I've spent all of 30 minutes studying this, so, hardly an expert. But it seems like the genesis and ongoing purpose of P.E. accreditation is to protect the health and safety of the public. There have certainly been some high profile examples of poor software engineering affecting health and safety - thinking about the Toyota acceleration issue and the VW emissions scandal - but I am wondering if people really think an accreditation body would prevent this sort of thing from happening. What would a Professional Software Engineer be, and why would they be inherently better or more qualified than what we have today?