We always tip the folks that bring water & soft drinks , etc, to the table
On HAL ships, if you are eating at the buffet you would get your own water, tea/coffee and there is already a 15% "tip" added to soft drinks, so you'd be tipping the waiter extra if you did this.
The point everyone is trying to make is that if you remove the auto tip, the extra tip that you might give a crew member has to be put in the pool and shared with all the other crew members.
It's really up to you want you want to do.
By the way if you do remove the Auto Tip, then you will get a letter and I believe have a meeting with one of the Senior members to explain why you are doing this. I have no idea if it is the Front Office Manager or the Purser or who, does this.