Yes there are people who will ignore their symptoms on board or "cheat" as you say and just go about their day. It happens absolutely everywhere, not just on ships. That is the reality of COVID at this point. There will be many others who self-isolate, test themselves, do the right thing for themselves. Again at home or on ships. Let's just accept that, be done with it, and focus on our lives and what we can do and control. COVID viruses will be with us for the rest of our lives.