Earlier quoted context omitted.
There is no such thing as truly passive - the assets in this case are being used by providing capital to the markets and holding shares of companies that may or may not succeed. That’s “doing something” with these assets. The family heirloom that could bring you over the threshold? It’s collecting dust. The stock investments incidentally ARE already taxed, whether you are actively managing them or if someone else is…
By the same tack, is there any such thing as 'passive' wealth, then? Some things like cars depreciate, and others (like gold and real estate) appreciate. Why should it be off limit to tax these things?
California doesn't even tax gains at a lower rate than ordinary income...