Why are you curious? I didn't say there were only two classes. I said there's been "roughly" two classes over the last 30 years. Add other classes if you want (billionaire tech owners who don't code, billionaires in non-tech fields like real estate or agriculture or petroleum, old-money San Franciscans, millionaire non-working property owners who don't know how to open a Google Doc), it doesn't affect the conclusions: "tech workers" (and the "tech owners" who pay them) are an important factor causing many of the problems in SF.