While directly there is a non-human interaction going on, indirectly it is still two, or more, people communicating and exchanging ideas. This is the same thing that happens in person but often without the emotional attachment (Not that people who don't understand that don't add their own emotional attachment)
The reality of the matter is that this is no less real than anything else; it is simply different and that may not work for some people. And often times I'll see people say "the real world" and "in real life" when they're talking about leaving LiveJournal or not being online more often; their problem is they don't know how to balance the two, like you would balance time between activities or friends, so they decide to cut it off completely. Would you cut off your phone if it interrupted time you were spending with a friend? No, probably not. You'd simply put it on mute and let the voice mail take the call until later.
The internet has an automatic voice mail feature; it waits until you're ready for it.