As John said, their ignorance is only exceeded by their stupidity
Prior to the 'millenium bug' computers were only recognising two figures in the DOBs, in fact in all dates.
Therefore the computers were unable to compute ages correctly. To manually correct the problem for all databases, for all people on those databases would have required far more manual input than was required to re-programme all systems to recognise a four date configuration.
Obviously, this problem was not limited to DOBs, but all dates were affected.
Thus all benefits, wages, salaries, interest payments, etc, you name it, it would have been affected.
Even updates for computer systems would have been affected because the later 2000+ updates would have appeared to be older updates than those dated in the 1990's etc. Therefore the newer updates would have been discarded for older updates.
It was only because of re-programming for the 'millenium bug' that allowed systems to continue to function correctly.