Icelanta
Times have changed oldtimer
At my old university (top 50 worldwide polytech, for context not to brag!) an average subject , e.g. Calculus, amounts to 5 ECTS = 140 hours study hours. Of those you'll get 7x3=21 hours of classroom instruction, which essentially is a condensed summary of the matter you should've already learned by yourself before coming to class. In other words 15% of the required study hours consists out of classroom instruction.
Distance learning / CBT follows or less the same principle and is maybe even better, since the university doesn't offer you detailed video lessons. Only books and 15% classroom instruction.
In summary, in the modern world it has become common for high complexity positions to be fulfilled by employees who are theoretically trained by a system comparable to distance learning.
However, ATPLs don't really compare to university. There is no requirement of deep understanding of the theories and principles governing the subjects, it is all about acknowledging simplified concepts and facts. There is no abductive/inductive/deductive reasoning required, no dissection or reproduction of any theory, no discussion nor research, none. It is just learning chewed and simplified stuff. ATPLs only require a fraction of the cognitive capabilities required for a uni degree (can only speak for engineering). If I had to compare ATPLs to anything out of the conventional school system, it would probably be trade school.
So please, why shouldn't cadet be able to follow distance learning?
Don't get me wrong, I am not saying ATPLs are easy, I get that the amount of information in short period of time can be hard. However, I am fairly confident that there is no discussion on the content: If you compare the content of an ATPL course with a university course you'd have a good laugh.