I think it’s the “just” that they are taking issue with. We are “just” neurons. But we demonstrate interesting emergent behaviors that, in principle, can be reduced to firing neurons but in practice we don’t understand and shouldn’t diminish with the word “just”.

fair point!

To insist it's "just code and math" is to fundamentally mistake the rules for the game. Knowing the rules of Go without playing grants no insight into strategy, just as showing someone the code for Conway's Game of Life without execution reveals nothing about the gliders that emerge. The profound dynamics of a system are not found in its static instruction set. To ignore this is a fundamental error, because these are recursive processes that iteratively rewrite their own context, a reality the "it's just X" argument completely fails to grasp. Of course Turing undecidability is the canonical example - can't predict if a program will halt without execution.