PADI recommends that divers stay within the limitations of their training and then extend those limits through some combination of training and experience. Since the maximum depth allowed for OW training dives is 60 feet, it makes sense for OW divers to see that as their current recommended limit. In reality, some OW divers have not been much bellow 20 feet (a popular OW training site near me has a maximum depth of 21 feet), so 60 feet might be pushing it for them. As divers gain more experience and training, they push those depths. A diver who takes OW soon after OW will have done a deeper dive, with a maximum depth of 100 feet, so that person has had training and experience to go deeper.
If someone were to do a bunch of deep dives on their own before taking AOW, then that person will also have deeper training and experience. The problem is that unless that person also has a certification card indicating some experience with deeper dives, a dive operation might not accept it, likely because their insurance policy specifies certification. It is easy to understand why. If you accept someone's word for it or an easily-faked logbook, then you are making a judgment. If something goes bad, then your judgment can be challenged in court. If you require a certification card, then that card, not your judgment, was the determining factor in allowing the diver to dive.
If someone were to do a bunch of deep dives on their own before taking AOW, then that person will also have deeper training and experience. The problem is that unless that person also has a certification card indicating some experience with deeper dives, a dive operation might not accept it, likely because their insurance policy specifies certification. It is easy to understand why. If you accept someone's word for it or an easily-faked logbook, then you are making a judgment. If something goes bad, then your judgment can be challenged in court. If you require a certification card, then that card, not your judgment, was the determining factor in allowing the diver to dive.
