Separate responses to different people should not be merged into one post unless the poster wants to do that.
I've been posting on bitcointalk for more than ten years under various usernames, and most interference by moderators is not about improving anything.
The “Horizontal Rule” button is there so you can add some separation between your responses that could be made within the same post. Creating separate, consecutive posts for each reply can be annoying and spammy. I made this mistake when I was new to Bitcointalk and forums in general, but if you’re not a newbie and have been around 10 years you should already know this is frowned upon.