Non-talkers drive me INSANE! Granted, I am a very talkative person and I love to talk so I am bias, but still. How else are you supposed to communicate with someone? Osmosis of thought? This has always confounded me. I'll see people who are good friends, but they talk very little to each other (from what I can observe). It's like... how do you know about the person? How does your friendship build? Is it magic? Where's the voodoo doll?
Kidding aside, this really does confound me. I actually want to know from non-talkers. How do you build relationships? Though I should point out, there is a difference between someone who is a quiet listener, and someone who just doesn't talk much. A quiet listener, prefers to listen and let the other person speak. But, they offer up feedback and will continue the discussion (I have a few friends like this, I do get strained sometimes but that's my own problem). They will share what they think, just not readily and it needs to be prompted. Someone who doesn't talk is someone who does have thoughts, but just doesn't feel compelled or want to speak them, or they just don't care. I just... I don't get it at all.
(I think this is independent of type, but I do agree this seems to be somewhat common amongst ISTP's).