You lost me at `With terraform, my HCL modules worked no matter what language the service is written in`. With terraform your HCL modules only work if they are written in an obscure language called HCL.
Norvig addresses this at the end of f http://norvig.com/Lisp-retro.html . Basically these old AI techniques are now considered regular programming and modern AI is focused on ML. Both are useful but for different tasks.
I don't think it's always true, but in my case because the open source versions have more and better functionality, more flexible design, better documentation, are already known and used by thousands of people (easier on boarding), and maintained by a large community. It's true it has some functionality we don't need, but a couple megabytes of memory is pretty cheap relative to all the other things.
What is the rationale in making something like a hearing aid require a prescription? I can understand addictive drugs, you don't want them misused. What about the million other things that require a prescription?