They'd never have lasted thi slong if the ratings hadn't been so strong and the show's budget helped finance the lunacy. Imagine -- the past two hundred some odd years of looking, using the best technology of the day, hasn't been able to defeat a group of ad hoc adventurers who used some block and tackle slung over a tree limb to build it.
And that is one of those Oak Island myths - like that silly one about seven people must die before the treasure is found - that has no traceable provable basis in fact.