I've seen this over and over in SF and now rarely eat out. Many friends and coworkers are taking the same approach, most of whom never used to cook at home. Scamming your customers 5, 10, 20% at a time doesn't seem like a great long term strategy
I've basically given up on restaurants entirely. Even without ridiculous tipping and other surcharges, prices have gotten out of control. The food just isn't that great, and restaurant food is not known for being healthy, with excessive amounts of fat, sugar, and salt. The only function it fulfills is that I'm less hungry after eating it.
So these days I just prepare my own food. It's better in so many ways: cheaper, healthier, faster, no risk of disappointment.