There's a good chance that a millionaire came from old money. That doesn't make them inherently interesting. The ones who are self-made, the anomalies in that population, are more likely to be interesting.
All kinds of writers, artists, scientists etc were once from that group.
So it's more probable to listen to something interesting from an old money millionaire who inherited wealth, than from a self-made one (which would tire you with self-promotion and gloating about their business acumen, bravado, and hardships they had to overcome).