This thread is brilliant, I have worked about 6 years of my life in the hospitality industry and I have got out of it because it is horrendous, you get paid a minimum wage, regularly work over your contracted hours for nothing more and generally have to deal with a wide array of people some nice and some not. I've worked in bars, hotels some nice and some not so, doing a wide array of jobs from waiting on to running restaurants/bars/weddings.
To put it simply, english people don't tip simple as. Sure there are a few that do, but all in all more often than not they just don't!