It was a courtesy that was expected and a courtesy that was given. Boxmen would tell new players to wait, and players waited. New players would never buy into a game to interrupt the flow of the game and the cadence of the shooter. Probably the most basic tenet of craps etiquette was that new players coming to the table would wait to buy into the game when the dice passed to a new shooter. And then the business changed and so did the procedures and long-held traditions of craps etiquette were lost. Everyone knew the rules and the procedures and there was respect of all by everyone. Caesars Palace used to have the finest craps pit in the industry with professional dealers and savvy players. The last remnants of casino craps etiquette died about five years ago at Caesars Palace in Las Vegas.
Here's my collection of written and unwritten rules that make up Dice Etiquette.