I am not sure exactly how this falls under political correctness. That phrase seems to have become the catch-all term for things people don't like. I think it is much more likely that what has happened in the past is that folks on the DDE or other plans have been tipping a percentage based on the discounted amount, not on the full amount of the check, thus shortchanging their servers. I seem to remember a CM some months ago on this board mentioning this policy change as being part of their new work contract and the workers wanted it as part of the agreement for the reason I stated.
Also, I think of this as Disney instituting a tipping floor, but not a ceiling. I imagine we will be able to tip above that 18% and servers will be working to get that bit extra. I hope this is enough to ward of worker apathy. I also hope this only applies to table service locations as I can't see tipping counter service folks 18% for just handing me my food.
First, a tip is not an entitlement. If it is, then add it to the cost of the food or have a line item that states "wait staff salary/costs." In Europe, you may add 5-10% for a job very well done, but the cost of food does include the majority of the service personnel costs.
Second, somewhere along the line I think we have forgotten what the original purpose of a tip is: something extra for a job well-done, the amount to be determined by the quality of the service. Also, it seems that somewhere in time, we have increased the percentage of the bill to which the wait staff feels that they are entitled. It has risen from 15% to 18% even as the cost of the meal has increased. And, for buffets, 18% is quite a bit above the norm to tip.
Third, I think Disney needs to consider their customers as well as the demands of their union wait staff. (At this point, they are beginning to drive away both long-term and potential customers with the multitude of extra costs written in the fine print. When people begin to calculate the cost of Disney, many other vacation options look great, and the actual days spent at Disney during an Orlando vacation begin to dwindle.)
Fourth, we have DDE, and we make a point of calculating 20% from the "before discount" price for the tip. However, I am so offended by the "union workers" sense of entitlement that I am changing my expectations of their service. Honestly, at this point, if the service isn't excellent, I am offended enough to consider calling a manager over and discussing my service expectations for the tip amount I am forced to pay.