My dd has been a waitress while doing her A levels and I'm always shocked by how mean some people are and how little they tip, so I don't think an automatic service charge is a bad thing. If it goes to the staff and chefs, that is, and not into the owner's pocket!
But do you not think it might just be the owner who is being mean, by not paying a fair wage to their staff? Or is it that your DD does earn a fair wage for the job, but you'd just like her to be given more?
I really hate the attitude that customers in any industry who pay the bill they are presented with in full, based on the pre-agreed price for the goods or services, are being 'mean'. Do you think that, if a customer is extremely friendly and super-polite to their server, the server should knock some money off their bill?
Tipping in restaurants probably originated from the times when staff were paid next to nothing and the customers were all extremely well-off upper-class sorts; but nowadays, there's much more of a balance - it's often ordinary people buying goods and a service from other ordinary people.
As PP said, some people save up really hard to afford a meal out for a birthday treat and simply aren't in a position to chuck in another £20 or so without even missing it. If I need £50 of carefully-budgeted-for food from the supermarket, should I consider that I must do without it, or get less food than my family needs for the week, if I don't have an extra £5-£10 to bung to the checkout assistant for doing the job they're already paid to do (already built into the cost of the food)?