Because you have to understand the nature of risk is one of probability and consequences. If you run that rapid, what are the odds you'll flip? If you flip, what are the chances you'll swim? If you swim, how likely are you to get hurt (or killed)? Just because you get a certain result in a single roll of the dice doesn't mean it was likely or that the outcome was a result of skill and ability instead of pure chance. Most people, if they paddle away from a rapid, take that as evidence they made a good decision without critically examining what actually happened. Aside from leading to a false sense of confidence that will ultimately lead to disaster it also is a missed opportunity to learn from your mistakes without having to suffer negative consequences first.
Studies have shown leading factors in deadly accidents for experts (people who have enough experience to presumably have good judgment) include underestimating familiar dangers and an unwillingness to re-evaluate decisions once they commit, even if a bailout presents itself. There's also lots of evidence that humans love to engage in ex post facto motivated reasoning: using our final position to justify the reasoning that lead to that state. We can do better, but only if we're aware of our natural shortcomings and create a decision-making model that includes our weaknesses and deliberate steps that help us identify and overcome them.
So if you run that rapid, get offline and flip, but roll up in an eddy instead of getting pushed into a sieve, count yourself lucky but also realize your decision-making was possibly flawed. If you take a newbie out on the ocean on a big day but manage to do a T-rescue before they crash into rocks and they don't realize how close they came to being reduced to sausage, instead of pretending everything is fine maybe admit it was a bad idea.