We still have bank failures pretty regularly. But they're a small fraction of total volume, and the damage is contained thanks to regulation. Since 1933, every bank depositor in the US has had insured accounts. And the bank failures that happen are not of the "oops I losted your dollars" variety. E.g., the most recent one, the First National Bank of Edinburg, Texas, was just a pretty normal business failure. Nothing was stolen, the regulator arranged a merger, and no depositor money was lost.
It's true that Mt Gox might have lost some money even if they had been following known best practices. You're right that Bitcoin is new, and presents new risks. But they wouldn't have been driven out of business with hundreds of millions of dollars of losses. Money given to them by people who were just as credulous, just as believing that the old rules didn't apply.
Yes, there will always be fools and financial scammers. But the proportion and the scope in the cryptocurrency world is much, much larger. In the short reign of the *coins, there have already been enough disasters that somebody has managed to fill a book with them: https://www.amazon.com/Attack-50-Foot-Blockchain-Contracts-e...
And I'll note that I'm not saying the entire space is "idiots and children". Just that the tolerance for incompetence and scam artistry is much, much higher. Which, given that you defend it as being the "wild west", you apparently agree with.