The structure apparently was inspected several years ago and declared sound. I suppose one can always say "more thorough inspections!" but it looks like this was a surprise and would have happened on any reasonable budget.
You can design and inspect things like they were aircraft, but then everything you do is a large multiple more expensive. It’s hard to think of a one of a kind instrument that is an enormous outdoor installation failing after 57 years in operation is an outcome that deserves any blame.
It's also due to the nature of how it was built and assembled. You can't lower the big suspended machinery in the middle without dismantling the dish underneath it.
It is possible but far from certain that inspections could have found and fixed cable problems before ultimate failure.