OK, so where did you come up with 80 minutes?
Just an average I see that is got for an course. Don't call the rental hours of the pool, but the real time that is spent in the water.
Setting up equipment is super simple, you just need to do it a couple of times. Some do it after 1 time, others need 5 times, but then everybody can do it. Only after a course it still must be done, and not a dm that takes it over.
But this is a typically dryrun that is practised in a course. The same with hand signals .
Making a course longer, yes, it will improve the overal results of making a better diver. But diving is also a lot practising, so things you can do yourself. And the most important thing is that if you make a course longer, the commercial chimney must smoke. So that means the price will rise. And also the time needed. 3 days is for a lot of holiday-starters doable. But if you make it 4 or 5, you will loose customers.
Also for clubs, if a course takes 6 months, what is quite normal here, you wll not attrack some divers. Or divers run away when it takes too much time.
I started after a commercial ow (3 weekends) with 2*/aow with a club. 3 months later it was still not finished, it was still not officially started. So I did in 1 weekend an aow course. Then I started the 3*/dm course. 6 months later only theory was done, so I finished my dm course in 1 weekend somewhere else. And then the club started complaigning. But why? I did nothing wrong, I just wanted further.
So yes, you can improve the level when finishing aow. But does this mean statistics show lower accident levels? And do you still teach the same amount of courses? Of will you loose customers? If I course did not cost 450 in my time, but 600, I would not have started diving, I simply had not that money at that time. So don't look at the level after a course, also look at accidentstatistics and the commercial part.