There's obviously a clear relationship between the accident and the way they chose to respond to cut costs. But the key word there was "chose". They didn't have to close and remove what they did at the time, including Sub Terra if they didn't want to or had any kind of even medium term strategy. They didn't have to keep everything closed for so long, they didn't have to make the decision to not invest in long term additions and it had no impact on all the axe swinging they did before the accident even occurred.
100% agree with what you're saying though as cutting their cloth accordingly was inevitable, of which I can understand why a cost heavy and not particularly well received attraction like NST was temporarily mothballed. I just think the accident gets blamed a lot for poor decisions over many years both before and since. I mean, in terms of NST it's been sat there for 6 years now. They would have known Submission and Ripsaw where on the way out a long time ago and this is the 7th season of widespread 4pm closes. Other than moving the deck chairs around, Food & Bev offering and CCL have never recovered.