You can solve anything with enough scripts, but that in no way invalidates his point that the abstraction level seems a bit off.
I'm not sure that his solution is really an improvement, however, because then you have to bake in the semantics for a fixed set of product types, and when that list gets extended, you have to bake-in a new one.
Not only that he wants to re-invent messaging and daemons, essentially.
There are pre-existing paradigms for service brokers, message passing, etc., they all try to solve this problem, and they all share this same fault, they become in-extensible...
Which is the core programming tradeoff, flexibility vs robust constrained behavior.
On the extreme end of flexibility you have AI goop you barely understand, but arguably it is far more flexible than anything you ever wrote, even if you can't make any guarantees about what it does, on the other hand you have these declarative things that work fantastic if that's what you wanted, but probably not worth getting into computers for...
This is a really good conceptual model, the tradeoff between flexibility and constrained declarative frameworks. The goals is to make self-hosting applications extremely easy and extremely reliable. With that as a goal, being highly constrained seems like the way to go.
I'm not sure that his solution is really an improvement, however, because then you have to bake in the semantics for a fixed set of product types, and when that list gets extended, you have to bake-in a new one.