Well, I have a problem with the perceived arrogance. It wasn't, "can you give me a second, Blue, I'll wrap this up real quick" It was "Nope!" To me, this may be an indication this coach intends to attempt to control the game. Some of us may have run into this type of coach before. I can tell you I did at a Men's Major NC in Lawton, OK once. He informed me how I was going to umpire the game. Yeah, that went over well.
Yes, Steve is correct, it depends on the situation and there is no single fix for every situation. The coach knows the game is supposed to start especially if s/he already has had the battery on the field and having completed their warm-up. You have to ask yourself if you are prepared to do this every inning? Are you prepared to what it may come to later in the game if/when it becomes a problem?
Just because there may not be a time limit doesn't mean there are not others who will be affected by unnecessary delays of their games. Spent too many years of league and tournament directors, local, regional and national UICs telling me to get the game started on time.
Unless a bus was late or a last minute schedule change, there is absolutely no excuse for a team to not be ready to take the field prior to game time which is first pitch, not the pre-game meeting.