I'm one of those people, and I know that isn't how to have a conversation. Thing is, I usually don't want to have a conversation. I don't like small-talk. I don't want to talk with people in general.
And that's something I can respect. What I respect more is when someone tells me that outright
That branches to a whole discussion about people not wanting to offend the other. Honestly, if you outright say I don't want to talk or don't want to talk with me, it's a lot better than pretending to care about the conversation and just give these one word responses.
Though my question to you I suppose is what is small talk to you?
I've never thought small talk to be conversation for the sake of conversation. It's always been seen to me as conversation with the purpose of learning something about someone, how they think, what their ideas are.