Half of the families in London sitting on hundreds of thousands in net worth earned around median in their primes.
The same is likely true in SF and elsewhere.
(As a side note, it's now impossible for people earning median income to participate in those markets, due to the expense).
EDIT: That said, I do think that income is over-emphasized in categorizing people as rich or not. A person who lucked into a house that went up in value might not feel rich, but they definitely are richer than the person that has to borrow a million more dollars to live in the house next door.
Which, if you are not counting, you are just being silly.
The man on the clapham omnibus will not tell you that a person who owns a house and works in the supermarket has a high income.
They might say that they're rich though. Because wealth is the thing that makes you rich.