One of our company's founders was fond of saying "A problem deferred is a problem solved."
Shortly after I joined the company, he went into semi-retirement and then limited himself to being on the board. I ended up running a group with responsibility for many of the systems he'd started. My maxim is "You never want to take over from a guy who's motto is 'A problem deferred is a problem solved.'"
All those deferred problems -- many, but not all, had to be solved later.
But in many ways, this was the right idea for a new business in a new area. If the company had gone under, nobody would have cared whether we did or did not solve these problems, and deferring them improved the odds that the company would succeed.
Today I ran into this quote from Albert Einstein: “A clever person solves a problem. A wise person avoids it.”
That sounds about right in the intellectual pecking order. Einstein would have avoided the problem. My predecessor was able to defer it and retire rich before the problem came back. I had to solve it -- or at least come up with a solution good enough to last for a while.
Meanwhile, those working on re-engineering these old systems assume we were just over-engineering the old systems out of the sheer joy of making the systems more complicated (or maybe because they think we were just dumb; I don't really want to know the answer). They throw away all those algorithms that bog down the system in order to achieve better efficiency -- until one of those one-in-a-million circumstances happens and the system fails.