I mean, there are very valid reasons behind it.
People are not expected to hold onto there documents forever, humans forget.. and change
Figuring out what happened 3 years ago is hard, figuring out what happened 30 years ago is near impossible & often wrong
This doesn't really seem like a valid reason & I suspect is misdirection.
If this were the case, litigating these instances would simply end quickly due to lack of evidence. There would be no cause for such a statute in such cases.