option markets work in silos, like currency markets, which make them very risky and prone to "arbitrage"
Again, please preach to millions of people online who trade options.
But you already made two false statements:
1. You wrote: "though selling his options might be tricky, no volume for all of them, so it has to wait until they expire"
I was discussing this specific topic and explained that volume isn't needed. If volume was needed then no options would ever be trading because all options don't have volume when first listed. While plenty of traders can make markets, regardless of their risk. Your post wasn't even about MMs' risk, but about the guy who simply may want to sell thousands of his contracts, and even I can buy these from him without problems while hedging. My risk has nothing to do with him selling his options.
2. You also wrote: "he actually got a CFA, I guess he forgot the chapter about price manipulation in the CFA curriculum".
Yet, everyone posts similar articles to his on Seeking Alpha, including financial advisors,traders, people fighting short sellers, etc.
BTW, Citadel and Virtu report highest earnings during periods of highest volatility, which is their main bread and butter. While Fed would bail out millions of options holders if suddenly millions of people would go bankrupt because they couldn't close their options (which wouldn't make sense anyway).