Having been a waitress many times in my life it is possible to remove a gratuity for a large party as I have seen it done. No one can force you to pay a tip/gratuity as it is a tip/gratuity at the discretion of the guest/client. If you want to have a service fee/charge then that is something totally different. Tips have become so expected that even carry out food joints have jars for the person that throws your food in a bag. I have to admit there has been a decline in the service in the last 10-15 years due to Carnival's cut backs in staffing. The whole service the cabin in the AM or PM thing and more cabins per steward and more tables for the servers at dinner. I am not Platinum but I have sailed mostly Carnival since 1999 and I myself had what I would call really bad service on the Paradise a few years ago. It was BAD, the cabin steward complained about how many cabins he had, the bar waiters by the pool were non existent and the one just plain didn't bring a drink and then told my friend oh we don't have that which of course they did as my friend went to the bar and got it. The servers were overwhelmed and the food was lukewarm at best by the time we got it. Not the usual stellar service I was used to. Both my friend and I having been in food service found it difficult to remove tips so we didn't but I would not want to go to guest services and be told I could not or my money would be returned in a month or so. ITS A TIP! A tip is for exceptional service given at the discretion of the person receiving the service not to pay help so the business owner doesn't have to. Once you have declared they will get a tip no matter what well you have opened the door for less than.