I have a good friend from the London area...moved here quite a few years ago - got married - 3 great kids - has his dual citizenship - lives in Michigan. We get together now and then but he always leaves decent tips. Maybe since he lives here he looks at it differently than your friends.
On the bar scene - I agree. My technique includes leaving a FAT tip right off the bat on the first drink.....it sets a nice tone for the evening IMO.
