I agree with Kuki and others on this issue except for the fact that it imposes a burden on those of us who wish to tip on our own. Why should we have to go to the Purser's Desk to have a charge removed?
Why not allow us to opt into this program by going to the purser's desk or by signing an authorization when we embark? That would be convenient and would reflect my wishes and not count on my inertia or reluctance to "rock the boat" (no pun intended). I know of friends who sailed on NCL when this system was introduced and they encountered considerable resistance and cajoling when they requested that the automatic tips be removed.