I think the problem I have with this argument is that it assumes 'Angry Alice' is there to argue in good faith. Unfortunately I've learned that there are many,

I think the problem I have with this argument is that it assumes 'Angry Alice' is there to argue in good faith. Unfortunately I've learned that there are many, many 'Angry Alices' out there that exist solely to rile up people and they get validation out of misleading people or tricking reasonable people. At the dinner party it's much harder to pull off this sort of trick because you're dealing with very real people face to face. Once you've caused large amounts of friction with people in reality, they're less likely to engage with you and will outright avoid you. But when you're on the internet, you have an endless supply of people that you can troll. And often it's become harder and harder to separate the trolls from what people actually believe.