The point is probably, by making the assistant more human-like, you'll grow more attached to it and use it more, depend on it. Perhaps even trust it when it suggests that you should buy this or that, or that it cannot open the airlock, Dave. Also perhaps some focus group showed that you need it to be more human-like so it doesn't scare off tech-adversies.

Or some random dude at google thought it'd be funny. But I put my money on it being used for improving some metric somewhere.