Not This Argument Again.
The Y2K problem was very real. The reason it did not happen on a massive scale was that tens of thousands of programmers spent hundreds of thousands of hours reviewing and rewriting hundreds of millions of lines of code to correct the problem.
As it was, there were some isolated incidents, which were reported at the time - which dropped out of the news cycle quickly because they didn't crash trains or bankrupt countries - but they nothing like what could have happened had people simply laughed and ignored the problem.
BTW, NO reputable source EVER suggested planes would fall from the skies, nor things explode. These hyperbolic suggestions were circulated by uninformed people who claimed the problem wasn't real, much like what's happening now with internet security.