How is that hilarious when making the mistake first is how many people learn their lessons that get passed on to others? 
I still believe M'Tux took the wrong lessons there. He wasn't hacked due to strength or lack of strength of his password hashing, he was hacked by leting his database fell in the wrong hands. Starting from here, hashing algorithms doesn't "save you" of anything and enforce "strong passwords" will make your customers unhappy.
Proper security assumes that the server WILL be compromised and databases stolen. Password hashing is precisely intended to minimize the damage from such an event.
So while letting his database fall into the wrong hand was one of his many mistakes definitely, it wasn't the key. The most damning was using plain unsalted un-iterated md5 to hash his passwords. That meant one single run of md5 would be sufficient to brute force the entire database. For those who already have existing rainbow tables, it will take seconds to crack weak passwords. For those who don't, it takes only minutes to few hours to generate the rainbow tables for weak passwords (up to say 8~9 characters) making it very profitable to do so.
If he had employed commonly available password encryption libraries using better hash algorithm like SHA256 and blowfish, with password stretching to strengthen weak passwords, it would had made the attack unworthwhile because of the cost of even cracking one user's password.
The real irony here is that this computational cost is what protects the bitcoin blockchain yet the largest bitcoin exchange was not making use of it.
While the specific lesson from the mtgox fiasco was related to weak hash algorithm, his sensitivity towards all forms of possible compromise should be heightened due to that. So I don't think it's fair to say he learnt the wrong lessons but rather he likely learnt more lessons than just the one he got hit with.