Dialog works because my perception of my interaction with software is that I'm in a dialog with it. When the interface mirrors that idea back to me, there's a fit or congruence and it feels comfortable, in the same way that an ergonomic handle is something like the inverse of the shape of your hand while holding it - I say "my profile" so the interface should say the linguistic inverse: "your profile". IMO, it has nothing to do with humanness or friendliness or emotion -- which is nice if it's contextually appropriate, but it can be irritating -- and more to do with cognitive ergonomics.
The idea of making computers more friendly, like a human, to make them easier to use is kind of a dumb idea when you think about it, like saying screwdriver handles should be shaped like human hands because we find it comfortable to hold someone's hand. Anyway, human-to-human interaction is often very awkward and definitely not intuitive, why should it be the ideal for human-computer interaction?