If you're going to visit a country where tipping customary, why not follow local customs. Have you never heard the expression, "When in Rome ..."? Would you bare you soles in a country where it is offensive? Would you reach for the communal food bowl with your right hand in a country where locals would be disgusted? We read a lot about "ugly Americans" overseas. I guess there is a counterpart to this.

Personally, I think the motivation for most who stiff the server is economic (they are cheap) whether they can admit that (even to themselves).