If you can get more people out and on board knowing they are vaccinated you can offload them quicker and turn the ship straight back around to get more. If you get a outbreak on board
Then that ship will be out of action, the port may not allow people off and you just lost s ship.
Any, any contagious virus is the last thing you want onboard a packed cruise ship. And that's the point. No-one is saying covid a deadly disease that will kill everyone.
If you did get a outbreak on board one of those evacuation ships it would just result in another massive problem. So take steps to lower the risk and get people evacuated.
fuck the outbreak that may or may not happen ffs, are you slow, look at the survival rate even if it did happen. The massive problem is leaving people behind to die..not catching a bug