You can't make a business of an honest marketplace based on selling services only to dishonest people. Eventually your own customers will ruin the business.
This is the fundamental reason "Organized Crime" always fails in the end.
I don't think it is true that Organized Crime fails in the end. OC organizations like Cosa Nostra , Yakuza, Triads and many others are not disappearing any time soon.
Look closer at what you are calling "organizations". I would just call that an Industry. The individuals and businesses (Families) fail at a rapid rate. Just because they are replaced by other businesses in the same industry, doesn't mean that criminal organizations are successful in terms of longevity.
There are some notable exceptions in the Yakuza, but I would argue even those fit the pattern because the most successful Yakuza are working in grey areas and aren't fully engaging in illegal actives.
Usually because someone ends up betraying them, e.g. the Chicago Outfit. In other words, dishonesty ends up ruining them. So the comment still makes sense.
This is the fundamental reason "Organized Crime" always fails in the end.