Isn't the biggest problem between a human and a bot is that they have nothing to talk about? The bot isn't from anywhere, it doesn't do anything, there's no reason for the conversation, and the bot isn't aware enough of context to speak about a topic in an intelligible way.
For my money, the most realistic chat bots will be the customer service ones: you have a reason to "talk" to them, they have a fixed identity, the context of your conversation is clear, and you share a common goal.
You'd think so, but people spend hours talking to chatbots. Well, good ones like this anyway. People like to talk about themselves, and the bot will ask questions to keep the conversation going. There's no social anxiety really because you know it's just a bot. And people love probing the limits of the bot or trying to get it to say silly things.
Of course I don't think the current generation of AI is anywhere good enough to be more than a novelty for a few minutes of fun. Maybe in the next few years. NLP is improving quite a bit every year, as are many other areas of AI. Google's chatbot trained just on movie scripts was pretty impressive. Though I don't think it would scale cheaply to millions of users. IBM's Watson has the same issue.
As for customer service bots, I'd love to see them become more general. Rather than just trained on one company's customer service data. Like a bot trained on all of stackoverflow that could specialize in discussions and questions about programming.
I made an irc bot that searched reddit for answers to questions. It worked really well, surprisingly. Especially on certain classes of questions that were likely to have been discussed on reddit before.
I would like to see more granular numbers for how long people spend talking with chat bots, because that's a distinct possibility! I've seen numbers like "x thousand hours of conversation", but my impression is that it's tens of thousands of people messing around with it for 5-10 minutes rather than anyone (or no more than a few outliers) spending any significant amount of time with it.
As for the reddit irc bot, that's a genuinely cool and useful project, but that's querying a curated dataset rather than having a coherent conversation or identity, so I think the intentions are fairly different. On the other hand, if you had a bot that only queried the comments made by a longtime user, you could get a pretty life-like effect!
For my money, the most realistic chat bots will be the customer service ones: you have a reason to "talk" to them, they have a fixed identity, the context of your conversation is clear, and you share a common goal.