A common objection to neoclassical economic ideology is that the ideology posits people as rational pleasure-seeking machines and that reality is much more complicated than that, and any attempts to mold policy away from real observations in order for it to resemble the favored ideology tend to make things pretty miserable for everyone involved.
I think this objection is partially true. It would be more accurate to qualify one's definition of "machine." If we are talking about the machines humans make, then you can you point out that neoclassical ideology makes use of an old conception of a machine that is built on a simplified understanding of what machines are and how they work, because this is an old ideology that was beginning to be formulated not long after the Industrial Revolution when our technologies were simpler.
So the understanding is simplified because we made simpler machines back then. Human intellect often makes analogies between observable reality and its own invented technologies to better understand things. It provides a framework to organize all that data. Lots of data gets lost when the framework is more simplistic. So ideologies like these can be useful for certain expediencies, but they shouldn't be clung to when they are becoming outdated.
Really all living things are sorts of machines. But they are highly complicated machines that are produced by mechanisms with millions and millions of years of evolution behind them, whereas human machines are very crude and simple in comparison because their life span is roughly equal to when we started to make tools. But then we are learning more about the natural world everyday and our technologies reflect those deeper understandings as we apply what we have learned from nature and even our own technology to better manipulate the world for our own needs.
But yes, it is always a bad idea to attempt to make reality resemble your creations. The former is potentially infinite and the latter is a construct. Reality will very dependably refuse to be crammed into a temporary box.
