Everyone seems to be taking extremes here. Boat crews absolutely provide
reasonable assistance. The question is "what is
reasonable in a specific case?"
I once led a group trip that included a diver with a chronic hip problem. He struggled to get off the boat, and he could not climb the ladder with gear on. We had alerted the dive operation ahead of time, and they were fully prepared to assist. That assistance was done so efficiently it was barely noticeable. That diver, however, was not doing technical diving with double tanks on his back and carrying deco bottles. If they had had to provide that level of service in a technical diving situation, it would be, IMO, too much to ask. He would not think of attempting that, though, because he had the common sense to know his limitations.
This thread started out, frankly, as a gender issue.
Donna Tobias was the first woman to graduate from the US Navy Deep Diving School, where she had to wear 200 pounds of equipment for every dive. She was then given very limited duty, not because she could not handle the work--she had proven she could--but because she was a woman. Those days are gone. I cannot think of a time in my diving career in which I perceived an expectation by anyone that a diver could not do something because of her gender. In the Navy, Donna Tobias showed she could handle the physical requirements of deep diving, and she should not have been prevented from doing so. If, on the other hand, she had not been able to meet minimum requirements for the job, she would never have graduated.
So what are the minimum physical requirements for tech diving off a boat, assuming that the crew will provide
reasonable assistance? I don't really know, because I have never seen anyone who did not meet those minimum physical requirements. I think that is because every technical diver I have met has enough common sense to know what those minimum requirements are. When I shattered my collarbone and a bunch of ribs in an accident and finally got the OK from my surgeon to resume diving, I did not attempt it until I made sure I could do everything that would be expected of me, and I assume pretty much everyone else would do the same.