Interesting what people feel is an umpire being a "good blue". Getting involved with things not inside the fence line is not being a good blue. Parents or anyone yelling pitch location is not against the rules. So you think the umpire should rule insportsmanlike conduct on a runner on 2nd base giving hand signals for pitch location to the batter?
It is not against the rules, it is not unsportsmanlike conduct and an umpire should not get involved with things going on in the stands unless it crosses the line of being threatening or vulgar. And even then the umpire should not address it themselves, they should get the tournament director to take care of it. The example you just provided of the umpire telling the people to stop using the batting cage, he was going to punish the teams playing for something people not even involved with the teams were doing and should probably not have even been paying attention to in the first place.
It may not be something for the umpire to get involved in, and it may not be against any rules, but to say that it's not unsportsmanlike...... well, let's just say I disagree with you. Personally, I think it blatantly takes away from the game.