Yeah, this is one of the few things that really piss me off. And the worst thing is when it's not the average joe who scurries off and mocks when you try to bring depth or true interest into the discussion; the shittiest situation is when the person is intelligent, and you can see that she's got a lot to say, to share with you, but she's overwhelmed by this "being restrained" mode, where you cannot reach a really deep level of sincerity and establish a personal bond. And sarcasm/joking off is a most effective shield for insecure people.
Belial, I remember we were having the same conversation on another thread some time ago... but this question is of great importance to me, and I'm thankful that you dedicated a whole thread to it.
D Mullholand