The original point was: "The idea that you can engineer yourself an addictive game is a silly concept."
The rebuttal was: "this is literally what casinos do"
The rebuttal to that was: "well, some casinos fail"
Which isn't really a point. Some casinos fail, that doesn't show that they don't optimize for addiction. It just indicates that optimizing for addiction is necessary but not sufficient for a casino to maintain solvency.