The Fed sacrificed the foundation of middle class wealth--stable housing values--to boost bank profits.
Lest you think the phrase "death of the middle class" is hyperbole, please examine these two charts, keeping in mind the middle class by definition must be in the middle of income/wealth distribution--conventionally, between 40% and 80%, i.e. the 40% between the bottom 40% and the top 20%.
See that little red wedge? That's the bottom 80%--the entire middle class and everyone below the middle class.