Should people not complain about unannounced changes to the contents of their food or medicine because we don't understand everything about how the human body works?
I'm not sure I understand your last analogy. How would changes to the human body change the contents of the food that is eaten? It would be more analogous to compare it with unexpected changes to the body's output given the same inputs as previously, a phenomenon humans frequently experience.
There's some added flavor because the LLM is indeed non-deterministic, which could make it harder to realize that a change in behavior is caused by a change in the software, not randomness from the LLM. But there is also lots of software that deals with non-deterministic things that aren't LLMs, e.g. networks, physical sensors, scientific experiments, etc. Am I getting more timeouts because something is going on in my network or because some software I use is A/B testing some change?
You may want to review that statement.