Not saying you are incorrect, but that's not the full picture.
Not engaging in a two way conversation is the opposite of showing interest IMO. People who give one word answers, answer a question and don't ask anything back. They don't want you to reply, but apparently they've got not much else better to do so they reply. It could be related to an ego stroking as well.
If it comes down to it and you ask them 10 questions In a row without them asking anything back, how can that be seen as interest or even someone youd want to keep talking to? Like others have said earlier, they are just talking to themselves and you would be too.
Well yes it's certainly more complex but if you think everyone is annoyed or bugged by your messages yet still responding that's likely only true if you have a small sample size.
Yeah one way conversations are annoying especially when they answer enthusiastically yet don't pull any weight themselves in keeping it going. I don't think I have stuck around for 10 questions, maybe 3.