But you're not putting it in context of the OP and what she is referring to.
Would you go and stay with someone, a relative, or even a friend, and tell them everything there is to know about yourself in length when asked, or unprompted.. but not ask them a single thing in return, or show any interest in what they are talking about?
And even when OP volunteers a piece of information, off the top of my head:
"I was thinking about doing race for life this year" you would just stare at them blankly forcing them to have to continue on unprompted (awkward) or just gave up under the assumption that even though they are a relative and are staying with you, they give absolutely zero fucks about you or your life or what you are doing (rude).
In OPs context it's a very selfish way to communicate IMO, I have a sibling like this and I know EXACTLY what OP is referring to, they will ask to come to see me for coffee and a chat, but apart from their basic "I'm fine" type answers, I have to be the one doing the heavy lifting of the conversation, and thinking what to ask them and what to say to keep any sort of conversation going while they sit there and talk in little more than one word answers, OR they talk at length about their life, and their job, and their hobbies etc while asking you nothing in return, it's very one sided.
I did a secret experiment not long ago and apart from the general how's things, which got the usual 'fine' I purposely didn't ask any questions, in the hope that they would pick up the slack (thinking maybe it's me and that I lead too much) but honest to god we just sat there in silence, she didn't say a word, she didn't volunteer anything or ask a single thing, after about 10 minutes she said she had to get going.. I found it excruciating to be honest, but it proved a point that some people are just shit at pulling their weight in conversations.
I completely understand your perspective about small talk, and passing chit chat, and no one actually caring, that applies to a lot of interactions (colleagues, people you see in passing, anyone you come into contact with who you don't know very well) but when a relative or friend makes a point of coming to see you for a chat and then shows zero interest in anything you are saying it's just bloody odd.