I have an idea how this might have happened, or at least contributed. Basically somebody ruins it for everybody type of deal... For instance, in the Mid 70's many guys were getting typed in Lears, typically 24D's, using the GI Bill. (It was about a 6K deal with a 10% Co pay as I recall) A portion of those folks only had Private cetificates that rendered the ratings practically useless. For that segment, who also had little interest in persuing a flying career, it was essentially a cheap joyride at significant taxpayer expense.