There's so much wrong with this comment. First, middle class _by definition_ did not have large estates that earned incomes for them.

Second, it's weird to throw in an "unfortunately" after pointing out that the only thing that enabled this was exploitative labor practices (including slavery!)

Third, most homeowners do not actually start a business and use their property to earn money.

Fourth, the home doesn't have a negative value. It has a resale value often quite substantial, and you are living in it while you're paying all those maintainence costs.