I never leave any coins on the exchange, I always move my coins to my non custodial wallet. This is why never trust any centralized party, it's just a gimmick if they offer the exchange has high security and insurance funds. At the end, you can't trust anybody words when you get disappointed by their fault and you can only blame yourself since you're careless.
In this case, if to blame, we should blame ourselves, not them because we said we don't trust banks and we choose cryptocurrency to reduce risk because of centralization of banks. But in the end, we can't get out of that vicious circle just for the sake of profit. I believe that the people who leave money on it are day traders, for the sake of profit, forgetting that risk is also lurking for them.
There have been many lessons about exchanges collapsing but people will quickly forget and centralized exchanges will never be lost.