That falls under "a certain amount of fraud going on". Yes, there were a lot of bogus AAA ratings going around. But everyone knew they were bogus - you don't get AAA paper that pays a 10% return. Any investment banker from the GFC era who tries to tell you they're a poor innocent rube who was taken advantage of by a dastardly ratings agency is having you on. The people buying the CDOs were sophisticated professionals who did their own analysis and bragged about how smart they were.
If you think this is not really happening, you are naive at best, complicit at worst.