The money has to come from somewhere. If cruises adopt a no tipping policy then the cruise prices will just go up the $10 per day you are tipping. Then there really will be no option.
As it is now you have the option of adjusting the tip at the end of the cruise. We usually adjust it up for everyone because the service is so good. We have only adjusted in down for 2 people in all our cruises. If you cant afford the $10, or it irks you in any way, then perhaps you shouldnt be spending money on a cruise? No one should cut a budget that close.