I'm going to throw in an extreme point of view (that isn't mine, BTW) here...
My fiancee is absolutely, dead set against tipping. Her feeling is that the expectation that a patron pay ANY tip unless the diner receives superior service is nothing but an excuse for the restaurant to get away with paying the waitstaff lower wages and pretend their prices are lower than they really are, so she won't leave a tip. Needless to say, this leads to some pretty uncomfortable experiences for me when we go out and she pays...![]()
To put it mildly, she's not happy about DDE implementing a mandatory gratuity. As far as she's concerned, Disney's just taken back most of her discount.
As weird as it makes me feel when she does this, I'll give her points for an interesting argument. Why don't restaurants just hike the prices 18%, pay the staff with that extra money and make it clear that a tip is only to be left if the diner feels that they've received superior service? At least the bill would be a more honest reflection of what the meal actually costs, and we wouldn't need to have discusssions like this one.
I'm more than a little puzzled by anyone who espouses a "philosophy" that in practice deliberately hurts hardworking folks. Here's hoping OP will be able to encourage girlfriend to feel some empathy toward the servers who are just trying to make ends meet by waiting tables. They're people, too.