The pattern I've seen repeatedly in real life is that a company does something they don't expect to be important and impactful, cutting every corner they possibly can to shovel out something that minimally meets the requirements. And then that software surprises everyone by actually being wildly successful, and now they have to support it and modify it to a state where they can build upon it. Which might be hard if the product is an unholy mess made by people who knew little of what they were doing and cared about it exactly as much as they got paid for it (that is, not much).

And cutting every corner to get the cheapest possible product out might not have even been the wrong call! Presumably most things made this way fare just as well as they were expected to and die quickly after being made, not spending scarce resources on making them better was probably the right thing to do.

It just sucks when you end up having to maintain strict backwards compatibility to something that was made in two weeks by one guy who took every shortcut on the way to duct-tape together something that technically does what was asked for. (Yes I'm thinking of you, javascript.)