The fact that you've totally missed the point suggests you should be one of those educated on the matter. It's more about learning why this MIGHT be offensive to others, rather than myth busting stereotypes.
But I can turn that around and say if Mina isnt personally offended then who's business is it to be offended for him if its simply light hearted banter and not inciting hatred?
For example what right does it give me to go on a one man crusade being a white male to start shouting at ann summers staff that their shop window ads imply black overweight women are not as represented in comparison to skinny white women... if no black overweight women are really arsed by it?
I could be offended if someone takes the mick out of scousers yet nothings ever said.
Thats the problem too much changes in society for the 0.2% that are offended for other people who are actually not offended at all... whilst real problems like unemployment, homelessness, stagnating economy and arms being sold to dictators go brushed under the carpet...