In perhaps one narrow sense. The middle class people who lose their jobs and savings, or whose welfare depends on economic activity (i.e., almost everyone) such as others buying, selling and investing in things don't do so well.
Perhaps there is some data on how well the middle class did in 1929, 1988, 2008, etc.
The ONLY middle class individuals that benefit from a crash are those with the cash to buy in at the depreciated prices.
Cash savings actually increase in value during crashes. Crashes provide the middle class with opportunities to purchase assets that they otherwise would not be able to afford.
I get that, but you have to have cash savings before you can purchase assets. MOST middle class individuals can't afford to keep their savings in cash. MAYBE they keep 6 months of salary in cash in the event of a lose of work, but every other saved dollar is put to work.
You'd have to destroy their life savings to give them a decent opportunity to buy assets on the cheap.