Non-glib answer: Art tends to hold value very well. For someone in that wealth bracket, this is probably a very reasonable diversification + having a significant amount of sentimental value. (it's Davinci, which even for a pleb like me would be neat to have in your living room)
glib answer: More money than sense.
Edit: I realize you didn't have "why would you" in your question and answered something you didn't ask. Apologies. (I nontheless maintain my statements :) )
> For someone in that wealth bracket, this is probably a very reasonable diversification + having a significant amount of sentimental value.
I can't even pretend to understand how people in that "wealth bracket" think. Imagine if you knew, or at least knew of, every person in the world with as much or more money than you (i.e. a few hundred). Imagine if you had enough money to ensure that, barring major wars or mistakes, all of your close friends and descendants could live comfortably without ever having to work another day. What would you do with the spare hundreds of millions of dollars? Build space ships? Build islands? Buy paintings? Buy paintings, only to set them on fire to demonstrate your power?
> (it's Davinci, which even for a pleb like me would be neat to have in your living room)
Imagine the maintenance costs. I'd keep the thing in a Swiss vault, and sell it to the highest bidder.
glib answer: More money than sense.
Edit: I realize you didn't have "why would you" in your question and answered something you didn't ask. Apologies. (I nontheless maintain my statements :) )