It doesn't matter though, does it, whether people tip or don't tip? It's not mandatory and never will be. Why would either 'side' impose their way of doing things on the other? As the for the name-calling, that's utterly pathetic. I wouldn't comment on somebody not tipping, if they don't want to they don't have to. I would do it - not because I particularly want to if it's not deserved but because it's the 'convention'. I wouldn't expect the head-patting that some on this thread are revelling in though... Yikes!
I tip, I don't much like doing it for mediocre service, rounding up and adding a £1. I think that we're celebrating and rewarding very mediocre service in the UK as it's the norm. I tip very well when the service is excellent - that's what tipping should be, I think. We're a bit mindless as a nation, following the crowd and doing it because it's always been this way... not exactly something worth crowing about, is it?
I would have liked to tip the lady behind the cheese counter in Tesco. I went to buy cheeses, didn't know much about them and she popped around the counter to come and show me and describe all the cheeses, what goes with them, etc. I thought she was an excellent ambassador for Tesco and I gave them feedback online later but could I tip her? No, emphatically not. Did she deserve a tip? Absolutely she did.
Stop name-calling those of you who are doing it, you sound like idiots and happy to be in a crowd.