Because people are losing the ability to talk to an actual human being in face-to-face contact. People spend more time talking to each other through texting and Facebook (I'd throw E-mail in there, but even that is going away) than they do actually talking to the person. It's apparently "easier" because there are no social ques to rely on, no eye contact, no appearance, no tact. You're not actually talking to the person, you're reading what the person wants you to read.
I actually find it harder to talk to someone online than in person, because I can never think of something to say. I get bored staring at a screen for over ten minutes. Plus, you can't have a real conversation. When talking to someone, they can interrupt you, or point something out quickly, and the conversation takes a different turn. Typing something up, your brain has time to filter stuff, or skip over something, or phrase it differently. Like this post. I can promise you that, if we had been talking face to face, you and I would have a very long, drawn out conversation. As it stands, I've said everything I wanted to say and you didn't get a single word in because now, I have to post it and wait for a possible reply. (Sorry if this comes off as a bit preachy. Didn't mean it that way, that's just how I see it. Again, one of the reasons talking online is harder--or easier).