Guest Services would never request that you stay in your cabin under quarantine, such order would come from the ship's doctor. Also, since cast members at Guest Services are not medically trained, they would likely expect an adult in any party to be mature enough to determine whether a member of that party should see a doctor. They also may not refer passengers to the medical office because there is added expense to the guest, it's not a free service. If a member of my family was ill and I wasn't sure if he/she should see a doctor, I would call the medical office and ask - just like I'd call the doctor's office at home and ask. Keep in mind that the medical office has a vested interest in billing for patients seen. I also believe it's the ship's doctor who maintains records about how many passengers reported certain symptoms, not the Guest Services desk; DCL certain receives the info, but not necessarily the Guest Services desk unless there has been an outbreak determined. While it may sound like a lot to say 100 people were sick, that's a small percentage of the population onboard a full ship.
If you called Guest Services and asked "I am sick, how do I get seen by a doctor onboard?" and it was shrugged off, then I'd agree DCL was avoiding the issue.
