What is this other than thinly veiled, generic climate change denialism? Black-swan events are by definition not something anyone can prepare for.
Why do we always have to end up with this false dichotomy?
Why is it so hard to accept that
a) yes the climate throughout the history of our planet (at geological time scales) had a lot of variation and humans didn't live during an average climate
b) it's reasonable to worry that the climate deviates quickly and strongly from what it was throughout the history of humankind?
Why do these two points need to be opposed to each other? The timescales are so utterly incompatible. Is it because people struggle to understand what a million years is? Let alone a hundred million years.
A lot of things we consider normal has only been averages for recorded human history, which has also seen plenty of climate outliers, and is only a small fraction of the total history of earth and life on it.