Most of the super-wealthy derive their wealth from owning significant ownership in extremely valuable corporations. Outside of hedge fund managers and Warren Buffett, most of the super-wealthy do not have sufficiently diverse investments whose annualized returns may cover the annual wealth tax bill.
Are you saying that most of the super-wealthy do not (at least to a certain point) diversify their investements? Or is your point that most super-wealthy individuals acquired their wealth themselves by investing (or founding) a single corporation themselves?