I agree that the primary residence equity counts toward “total net worth”. It is helpful though to be very specific when speaking about the subject. There is “total net worth”, which includes everything, “liquid net worth” or “investable assets”, which excludes RE and any other iliquid stuff (if you have a Picasso, for instance), and, finally, “total net worth excluding personal residence”, which does include, for instance, rental properties, but does not include, obviously, one’s personal residence.
It is by this latest measure that San Diego has 100,000 millionaires. I suspect that many of them wouldn’t make the cut under the “liquid net worth” category, but have second homes and investment properties that appreciated mightily over the past 10 years.