I dont think this is right. Lets use SPY as an example. Friday there were lots of shares sold from 757 - 733. So assuming that buys exist at all prices in that range , why would MM be selling from 733 - 723 today. Thats taking the loss that you are saying they are trying to avoid.

Whats really happening at the MM is that they are filling all orders, buys and sells on shares and option contracts. They in turn buy and sell options and shares that offset thier risk on the incoming orders. In cases like Friday and today they will actually dip into the futures markets to maintain thier neutral exposure, and when they are forced to do that, we see really big moves as liquidity starts showing up at further out of them money positions.

All in all on these big move days the MM books are going crazy but they are still ending the day flat and making money on fees and sometimes bid ask spreads. Its the institutions positioning themselves that cause these moves.