sorry for the downvote, but an essential function of a car is transportation - bullets don't transport anything (not even small things).
A horse is not a car, it does not even bear a passing resemblance, and yet both can be used as a mean of transportation.
If this is what we expect, the analogy holds and the implementation details don't matter.
That is, for the same input at different times, a real neuron will have different outputs; and its own ouptus may change its state. In contrast, the memristor, once programmed, always applies the same function to its inputs. Even if it can be reprogrammed with a different weighting, it can't do so based on its own output - at least not with any current neural network architechture.
This is it.