Skills relating to interpersonal relations become less and less needed as technology improves, labour becomes more and more compartmentalized and you no longer need social cohesion to get any commodity, you need only interact with the market. I agree that most people are better off talking to real people, but it's nigh impossible to force anything on as large a scale as society when it's not the easiest and most profitable choice for the individual(in this case chatbots are easier and more profitable than IRL social contact, at least for the people that use them.)
Lots of drugs have been problematic before more modern refinement methods, my problem was the framing of chatbots and the harm from them as a uniquely modern problem, when harm from social activity has existed as long as social activity has existed. People use chatbots as an escape from the intrisnic harm that is possible from social interaction.
People have been developing fake relationships and playing social games which end in harm and heartbreak for millenia but now that we're talking to a computer it's a problem.
The particular child abuse comment was retracted, there is nothing more to be done. You are holding him accountable for something for which he has already accounted. You are laser focused on the one wrong step.
Think of him what you will, that is your right, but brigading against someone for something said 20 years ago and later retracted is petty.(He was also arguing on the assumption that children can give consent, and that consent=> no bad outcomes.)
>he had to be convinced by victims that victimization is a problem
You're complaining that he came to the same conclusion as you, but first had to be convinced, since his first opinion wasn't the same as yours. No winning move. One wrong step = cancelled for life.