Lets just forget about divers for the moment.
When have you ever seen someone fresh out of school / university / whatever educational institution that has the ability to handle all but the simplest situations.
New divers like everyone else need time to develop on the basics they have been taught in OW, and hopefully the more learned divers out there help them where possible.
If you have to work everything out for yourself takes much much longer than if someone can suggest better ways to achieve your goal.
I agree that anyone new can benefit from the guidance of those more experienced. But to use your analogy, if I took a course at school say in auto mechanics and graduated (proof of my acquiring a predetermined and finite level of knowledge), was hired on this basis, but it was later found that I didn't have the necessary foundation to work as an apprentice (requiring the mechanics to teach me what I was already expected to know). Would it be reasonable for the new employee to
expect this?
I think that UsryTregre's comments are valid. If she asked to go diving with me as a Dive Operator, I personally would have no problem helping her without additional charge. I wouldn't do this in hopes of a "good tip," rather because she wanted to go diving, told me up front what the situation was, so I'd do my best to insure her safety and make the trip as enjoyable as possible.
On the other hand, I would be upset if four or five people on the boat
expected extra help as a result of poor training or health problems that they didn't disclose. If they had made the disclosure before the dive, I would turn-away those whom I couldn't safely accommodate. I'd apologize and explain the situation and hope to reschedule them.
For me (as I've already mentioned), it's about managing expectations. If I pay $300 for a VIP dive, I expect to get what I pay for. If I pay $150, I also will want to get what I pay for and won't be surprised if the services provided are less than the $300 package.
Personally, I don't certify anyone who can't look after themselves in a safe manner. I have spent a fair amount of effort donating my time to giving SCUBA introductions to blind children; but I wouldn't certify one unless s/he could meet the standards; in-fact surpassing these to my satisfaction. I no longer teach recreational diving for profit (I teach in a Club setting for free). Even when I did my courses were twice the duration as was required by standards. I taught longer courses because I felt it was necessary for the safety of the students. Too many LDSs are rolling out poorly trained students for profit. They are dropped on DO's, DMs and Instructors when they want to go diving. It is not a matter of a competent diver needing assistance or extra experience that's the real problem...