Oh, Grant, I am so envious of your career!! My career has practically been the opposite. In the 90's I worked for an organization that did soil and biological testing. They used equipment that printed results on very specialized thermal paper. This equipment was very old, not network capable. So, what technicians had to do was print the results on the thermal paper and then double enter it into either some custom program or an Excel spreadsheet. The company that manufactured this specialized equipment went out of business. Because of that the company the produced the thermal paper stopped manufacturing that. Rather than change equipment and use something new, the organization I worked for opted to buy the world's remaining supply of that specialized thermal paper, rather than work on replacing it. I and others were ready, willing and able to get new equipment and write the software (if necessary) to work with it. Nope, just buy the remaining world's supply of this specialized thermal paper and kick the can down the road. I left that organization shortly after that.
Years later I rejoined that organization, working in a different department. But I could see that the organization's habit of never upgrading anything, unless forced to, was still very much in effect. I can think of at least half a dozen examples of this organization's tendency to put things off until after the last minute has passed, but will related one. I was put onto a project to try and get data out of a really old data store that I had no experience with. I wasn't even sure what sort of database it was. And no one else knew either. The app that users use was originally written back in the early 2000's, by the Center for Disease Control (CDC). I contacted them and learned that even they didn't have anyone who knew the system, database, etc. (I get the impression that the CDC doesn't have the source code, either.) So, in this particular case because the organization had waited so long, it became impossible to do anything more with it. I'm not saying that organization has done the delay game for all things, but they have for some.
Now, Grant, to answer your question ("Tell me why rolling the dice and planning on good luck is the more sensible approach?"), my answer is only one thing; budget. Nothing else matters. They ask themselves, "Can we afford it now?" If the answer is no, then they kick the can down the road. It becomes a habit to kick the can down the road year after year.