I'm so sorry that you consider that a case of the politically correct lobby... But I am a non-smoker and while I believe in live-and-let-live, I detest having to look like a fish out of the water with my mouth gaping open because my nose is clogged up thanks to your smoke, nevermind smelling like an ashtray when I get off a plane after a 13 hour flight.
It's common courtesy and decency to ask whether you can light up, but in my time of working in an establishment where smoking was permitted, I have never had smokers asking for permission. That's not to say that all smokers are rude, but the general implication that 'if I can smoke, I'll smoke because it's my right to smoke, bollocks to the non-smokers, they can find themselves a different place' is obvious.
S.