We haven't changed. Companies will not spend more than they have to on IT if they think they can deal with it until next quarter. This was no different, plus developers of software didn't expect their stuff to become legacy and not updated with better programs. Memory was premium, so a few less bytes here and there that would work fine for a few years was what they did.

Half a century is a bit of a stretch, but I otherwise agree. It should not have gotten to the level of trouble it became, but I also dislike the implication in the OP that it was just a non-issue meant to scare people; it was a problem that indeed came to a head because many companies kicked the proverbial can, but a potential real problem nonetheless (especially in medical/insurance/monetary systems rather than "planes will rain from the sky" sorts of issues).