You disagree with the statement "there were always obvious fixes that could've prevented it" with the response "no no, these were very obvious fixes that could've prevented it?"

You're missing the point about complex failures.

It's that if this particular path were unavailable, there are countless other similar paths. At sufficient scale and complexity, hitting one of those other countless paths is virtually guaranteed.

Let's say I drive Los Angeles to New York City. You look at the route I took and say, gee wiz, aren't you lucky that a tree didn't fall right there on Route 66? If a tree had fallen there (if we had "patched the particular route you took"), you would've been screwed!

But that's obviously not true. There were an infinite number of routes I could've taken. Any one of them would be equally "obviously preventable" by the same hypothetical tree falling across the whatever road I happened to end up taking. But you can't put trees across every single path between Los Angeles and New York City. The smarter I am and the more complex the map between us, the more impossible it becomes to put trees across all possible paths.