So now that the basic "obvious" assumption that interes rates are nonnegative (an assumption of every financial model until 3 years ago) has been proved wrong,

So now that the basic "obvious" assumption that interes rates are nonnegative (an assumption of every financial model until 3 years ago) has been proved wrong, we all cry "foul". Just another finance "axiom" going burst because human beings are complicating things... Like in physics... oh, wait! It took 150 years to improve Newton (not precisely debunk him).