By not blindly, I mean we were required to be aware of dive time and average depth. The table number serve as the upper limit.of dive time at specific depth. I think you are right, that part is a blind trust based on supposed accumulated data. What I was trying to say is the " let's splash and see what the computer says" was not the way taught in the class.
This is not the way the PADI OW course is supposed to be taught either. As an instructor for my fun job (scuba) and my real job (not scuba), I can confidently claim that students tend to forget things that are presented in class, learned for the quiz or exam, but then are not regularly reinforced. And this is the difference between training from PADI and from GUE (or similar agencies): many PADI students get certified and then do not dive regularly, so what they learned is not reinforced. GUE trainees, by nature, tend to dive more than the average PADI trainee.
But to suggest that a PADI student does not remember proper dive planning, so it must not have been taught in their class is illogical and incorrect.