Has never bothered me and I do it myself sometimes. I don’t make generic “thank you” type comments usually, I just upvote people instead. So I won’t reply unless I actually have something worth saying. Usually I will have something to say, but not always.
Also depends how many replies. If I ask a question and one person provides the answer, I’ll say something. If I start a thread and it takes off though, I’ll just observe. And I think most people are that way, just because a popular thread can be a little overwhelming.