There are a lot of rules, laws and regulations we don't like and seem silly and many are. Even though we still have to obey and comply. It's part of the shipboard and maritime regulations. If you don't like the rule you lobby to change it.
There is a stop sign at the end of my road. I can clearly see if another vehicle is coming from both ways long before I get to that stop sign. Does that mean I don't have to stop? No and if I don't stop I get a ticket. Same goes for the muster drill. It seems silly and redundant but it's the regulation and after the PR
nightmare that Carnival Corporation took because some people hadn't attended a muster drill they will enforce it even harder. The PR
of someone dying is far worse than putting an old couple off the ship.
Just take the 30 minutes out of your life and go to the muster drill.