"When a management with a reputation for brilliance tackles a business with a reputation for bad economics, it is the reputation of the business that remains intact." -- Warren Buffett

I really doubt either Steve Jobs or Elon Musk could turn Yahoo around. With Jobs's Apple turnaround, he had the advantage of sharing (creating, really) Apple's cultural DNA; he didn't need to "turn around" a company, he needed to cut the fat and refocus it so it could do what it was doing a lot better. Elon Musk has never run a turnaround; his companies have certainly encountered difficulties, but it's easier to take a new organization with a strong mission and make it work than to take an old, sclerotic organization in a market that doesn't exist anymore and somehow make it relevant again.