I agree on the "breach of etiquette" feeling - when I feel it, the tip is adjusted downwards! With regards to "a living wage" - what is that? Seems to me even the richest in the world live to their wealth - so how does one determine a "living wage"?
But I do think there is a difference between tipping someone who is merely doing their job - and tipping someone who does more than their job. I can think of no occassion I have tipped at Starbucks, as I can think of no way they could do more than make my latte. I do tip the housekeeper as I always ask for extra stuff, which she has to take care of. I tip serving staff at a 5star restaurant 20%; but a smorgasboard only 5 to 10%. The 5 star has to provide detailed service - the smogasboard usually brings me a refill of tea.
Cab drivers are my sticky point - if I have no luggage, how can a cabbie go above and beyond - clean cab? No crazy driving? Thin line.
"Expected" tipping - no.
I can live with earned tipping.