Old School,
When I officiated high school football, it was not uncommon for coaches and fans to scream about my crew's rulings based on what they thought they knew about football rules from watching TV.
For example, I don't know how many times I heard someone yell, "That was uncatchable!" to protest a pass interference call, which was an irrelevant observation because the word "uncatchable" didn't appear in the high school rule book.
The same situation applies to this thread. You keep bringing up MLB examples, which shed no light on a situation that happened in a high school game played under high school rules.
You've heard from two high school umpires. Neither of us thinks the umpire was out of line to say something the second time a particular player hit the catcher in a game where nobody else had any trouble avoiding him.
MLB handles these situations differently. For example, I looked up the box score and play-by play of the last MLB example you provided. The batter was hit by the next pitch--which is exactly how we don't want it handled in high school games.