Alex, I agree with you- and want to also add that part of it isn't just what they'll get if they are quarantined or denied boarding... part of it is that people are afraid that even if they report an illness of ANY type (be it vomitting from eating something bad, vomitting from upset stomach due to seasickness, etc.) that it's always going to automatically be assumed as Norwalk or some contagious virus and boom- they are either quarantined or denied boarding.
If there is no way to know whether it's a virus or not and they make the standard of ANY vomitting or stomach problem being considered a contagious virus and making you either quarantined or denied boarding - then people are going to be afraid to report it unless they think they are really ill in that way... and some might be wrong about that and really have the virus!
But for instance, on our last trip a few nights into our 12 night stay at WDW my son- and ONLY my son of 3 children/5 in family- threw up once during the night. It was very obvious that it was from the hotdog he'd had earlier (don't ask me how I know- just trust me on that LOL) and apparently it hadn't been cooked well or kept up on temp (from buffet) or something because he has eaten hotdogs before. But he was not running fever, no diarrhea and only threw up that once. He was fine before & after and no one else in the family was ill- although we didn't let the children eat hotdogs the rest of the trip.
Had we been on the cruise- I wouldn't have reported that episode of vomitting. Why? Because they might (probably from what it sounds like...) have assumed immediately that it was a virus and quarantined us for 2 days even though it was vomitting from a hotdog eaten earlier.
In this case I would have been right about the illness and it wouldn't have mattered that I hadn't reported it- but in some cases people are going to be afraid that even seasickness is going to be assumed to be a virus and get quarantined- so they won't report it and it could turn out to actually be a virus- and by the time they know it... many others could be exposed to it and get ill themselves.
So in essence, them (ie:
DCL/dr) being SO paranoid about every stomach irregularity at all being a virus and acting accordingly IS going to cause people to report less... you're right- no way around that happening. And to be honest- for myself it wouldn't matter even if they DID say "we'll give you a free cruise if you end up being quarantined or denied boarding"- that would not make it up to me if we weren't really sick. If we were- great... but we have insurance anyway so that's not doing us any favors. But if we weren't- it's not going to make it up to me... who knows when we can go again or if we'd want to and risk being denied boarding or quarantined again for an upset stomach or seasickness/etc. What would make me report illnesses of any sort would be if they didn't consider ALL stomach irregularities as automatically meaning virus and quarantine for 48hrs or whatever.
I have worries about seasickness- out of 5 of us and this being our first cruise- who knows how many of us might have some seasickness on the trip. I'm going to try to come prepared for that as much as possible, even to staying on deck 2 to try to help that, but I worry that if seasickness (or maybe even eating foods we aren't used to eating- since we're basically an Atkins family now and DH tends to get diarrhea if he cheats & eats more decadent high carb foods now- his stomach can't handle change I guess) causes one of us to throw up- that reporting it would basically be the death of our trip (or atleast ruined a lot- if quarantined for 48hrs)... because apparently any diarrhea, throwing up, etc. is automatically assumed a virus infection that is contagious.
Oh and btw, my eldest daughter and myself both have a higher than normal NORMAL temperature. At this point I'm considering bringing documentation of that from our dr's to prove that we aren't running a fever should the need to take our temp arise. I'm only half joking about bringing those docs.....