Well... I'm not discounting the terribleness of Boeing execs, especially in the 737 MAX fiasco and the decisions that led to it. But even with perfect execs, they'd still be in trouble. Airlines aren't flying anybody. So who's going to buy new planes right now? Could a better exec have changed that? No.
But it's definitely true that the company would be in better shape to face this problem if they had been shipping 737 MAXes for the last year...