Are you asking about criminal or civil law? This was a civil case. The general reason for imposing filing time limits is that it's better for businesses and society in general to have certainty about outcomes rather than perfect justice. If a plaintiff tries to dredge up old issues from many years ago it just wastes everyone's time and clogs up the court system.

+1

Wasting everyone's time and clogging up the court system perfectly describes the heart of this matter. Plain bullying and hype.