In-game fun (including charicatures and spoofs of culture relatable to something IN the real world) never becomes a real-world issue for me. There might be a myriad of factors for this, and I am only spekaing for myself, of course. One reason I not offended? Because I can separate the two. If someone at the table becomes offended then it doesn't fly, of course, but I can't recall that ever happening as long as the content is handled as joke-content and not a presentation of how the real world people around the table see things. There is something deliciously fun about recognizable stereotypes which is why they ARE stereotypes. That's what they do all the time in comics, movies, and especially in South Park, Family Guy etc, so why can't we have a humorous approach that takes a few jabs at cultures or religions or the like in RPGs? The South Park viewer knows it's wrong IRL, but can still relate to the absurdity and fun of the non-PC-ness presented.
My political stances don't change to become less politically correct IRL when I play RPGs with content that isn't politically correct. But with more and more things becoming PC, RPG's actually give me reprieve from the constant feeling that everyone is offended about something, because it's all right for certain people to be a crazed mass-murdering warlord or massive chauvanistic prick within the context of the game's world.
I want to point out that having ONLY charicature material is certainly not the ideal though. As an example I'd rather have nine out of ten Japaneese-inspired RPG products be about cool gritty worlds with relatively high science for the medieval timeframe and honor-systems for samurais etc. Yet if the tenth product contains a sushi-merchant who works himself to the bone while bowing all the time, then that might still bring a chuckle. I know it's not how such a person is in the real world, but the stereotype can still be a fun sidetrek to have amid the more serious content.