No buffer region in the titration of strong acids or bases?
Strong acids and strong bases essentially completely dissociate. So if you're adding the strong base to the strong acid, the solution stays very acidic, then neutralizes, then goes basic with just a small amount of the strong base. 

With a weak-acid at the pK value you have as much $\ce{H+}$ as $\ce{A-}$. Thus a small amount of strong base or strong acid won't change the pH value much. That is the very notion of a "buffer solution."

So yes there is a rational chemistry explanation. :-)