Wealthy people don't need credit cards, car loans, and mortgages, and most other kinds of loans that would show up on a credit history. They may use them, and if they do they should have a really good score unless they're bad with money. But if they choose not to (as they'd be able to, more easily than others at least), there score would drop until their credit history was blank.
I would bet the vast majority of wealthy people have substantial debt. I mean, if you're going to buy a $10M home, why would you use your own money when the bank will load it to you for next to nothing?
