If a prospective pilot cannot achieve solo in 50 hours, then it is likely that, in the course of an aviation career, they will encounter an abnormal situation in which they will be found wanting.
When that situation arrives, they may die, members of their family may die, associates may die, paying passengers may die or unrelated third parties may die.
Would you knowingly get into a taxi with a driver that took seventeen attempts to get his license?
My opinion is that it is the moral duty of the flying school to be honest with the trainee, advise them against flying and refuse to accept further custom from them.
In my humble opinion.