oppo
Coach
Actually, we tell the players we'll wait until they return to start the game. The players have themselves to blame for not listening to their managers, assuming their managers told them in the first place.
If the TD or LD decides that only legal bats are to be there and lets people know, then in my opinion it then becomes a rule. Like many things in life, communication is key. That is another thing rules do. They communicate to the players what is expected. In your scenario, it sounds like there was a rule in place and waiting on them was a courtesy.
Secondly, what good does a rule do? Nothing. Players break/skirt/bend/argue rules all the time. Making it a "rule" will accomplish zilch.
What good do rules do? What makes a ball a ball? What makes a strike a strike? What makes a force out a force out? Why are you out after 3 strikes? Why do you get to walk to first after 4 balls? Why are you out if a fielder catches the ball? It is all because of the rules. Our entire society including the game of softball is full of rules because rules create order.