Set under the microscope of the D. Postulate:
It reproduces rapid enough, but with no slight variations.
Separately, it can spring out of thin air, or likewise primitive conditions.
If rust had slight variations it would become a new concept of an
iron based life form that would rule the universe.
Scientists have shown decades ago that amino acids
can form on their own in the conditions present at the
time our planet was forming.
Saying that amino acids are almost life,
only they can not
reproduce,
is like saying rust spots are almost life,
only they can not
vary.
Variation
The difference between rust and mildew is immense.