People with that much money often can't resist the urge to show it off.
Regardless of how much they've got, they'll move into the biggest, flashiest spread they can afford. If they have lots of extra cash, they'd rather spend it on the size and appearance of the house than on improvements. That's what insurance is for.

I know if money was no object, I'd certainly move into a classier pad than what I've got now, but I would never spend everything I could afford on a house. There are other toys on my list with higher priority.
I'd love to own a flashy sports car, too, but a $30k Miata would satisfy me just fine, I don't need a $200K Ferrari. There's something about a $3500 tune-up and oil change that brings me right back down to reality.