You're assuming it was written any time in the last, oh, decade or more? That's surprising. Perhaps you've never spent time in a cost center far outside the profit centers of a large enterprise, where things that work are left alone to do so, because you're not going to get investment in replacing them or bringing them up to date with modern best practices, because they work.

I mean, there are weekend hacks of similar age and quality, with my name on them, that I know are still in active service. Because, for all their myriad other faults, they mostly work, and everyone who works with them is used to using them and to dealing with the occasional cases in which they misbehave. These are not things which anyone rebuilds just for the sake of it. So they go on being used until they stop working entirely, and the the business replaces them with something else.

Whether or not that's a sensible way to go about things is an open question, if you like. I don't think it is, because these aren't the sorts of things which cripple a business if they misfire - or make much impact even if they don't. So investing heavily in them would seem like a waste of money, though perhaps you disagree. But the world need not be mad for this to be the way of things.