But most of the umpires don't acknowledge the fans, unless it really is called for—which is a good thing in the long run.
You are correct, as an umpire I typically do not acknowledge fans, unless I believe it is interfering with the game. Your original description sounded as if it did by calling balls or strikes on each pitch. If I'm that plate umpire, I will likely stop that immediately. If you are now saying it's not that big of a deal, then it probably wasn't and your first post was more of a venting.