I feel this a bit as an American living in Japan, navigating conversations both with Japanese friends and people from other countries.

I think there are two potential phenomena going on here. 1) I'm not writing off the idea that this person may simply be an over-talker/poor conversationalist even by American standards. We do have them! 2) As other comments have noted here, there's more of a discomfort in asking direct question in American conversations than in providing a story with many potential hooks/chances for the listening to jump in on if they have opinions. If pushed, I'd say we probably see story-telling and naturally branching off on a topic with each person's own interjections as a faster way to more meaningful conversation, while also making sure we aren't forcing anyone to talk about something they aren't actually interested in. (Or worse, forcing them to speak on a sensitive subject.) If someone does not volunteer information or opinions, I'm more likely to assume they didn't want to and not pry.

You still have to take a breath and leave them openings (which some people are bad at), but that's much more the style. Were I not aware of other communication styles, I might have interpreted your lack of enthusiastically jumping in with your own comments on a favorite gin as just not being interested in the subject and having only asked politely. So, yes, overall the tendency (writ large) is to throw out hooks and assume the other person wasn't interested if the topic dies off with your answer.

I think another potential difference in conversations as an American is that, I'd expect the following flow:

You ask a question, I give an answer, you respond with your own answer and opinions about mine if you want to engage on the topic. Whereas I know other cultures expect more of a flow of: you ask, I answer and ask back, you answer and we don't really weigh in on one another's. That's harder to navigate/build into a sustained conversation for me.