It's a silly exaggerated example. Point still stands, at least from my experience. Even with a rubric, people still (intentionally or unintentionally) find ways to do things that circumvent the learning goals/outcomes of the assignment
If the real objective is learning goals/outcome rather than (or in addition to) a working temperature circuit, then that objective has to be somehow encoded into the requirements. Or else, sometimes all the stated requirements will be met without that unstated one being hit.
This is difficult because, for instance, the possibility of cheating means that the person who says they performed the assignment might have contracted it off to someone else and learned nothing.
Someone who already has all the required knowledge can also just spin out the assignment without learning anything.
Basically, learning is a state change in the pupil; if you want to validate that some state change occurred, you have to have a way of measuring the state before and after and calculating a difference.
