Knowing that addresses may not conform to any arbitrary rules should lead to disabling automatic validation (or downgrading it to nothing more but suggestions, "are you sure that's correct?" hints).
Pretty much sums it up. Instead of a simple form and some "I have an unusual address format" check box that gives a more free form field we have people abandoning all restrictions.
And being burned by the total anarchy tried, there is the usual discussion about localization not being worth it that simplifies to "I don't believe those not like me should get my attention".
Knowing that addresses may not conform to any arbitrary rules should lead to disabling automatic validation (or downgrading it to nothing more but suggestions, "are you sure that's correct?" hints).
Not to stop offering users any guidance.