Personally I think some people are far, far too sensitive and go way over the top regarding political correctness. I honestly think that the comments regarding Mexico is an example of JC & Co. lashing out against the PC culture. Comments could have been made about the French, Germans or Yanks just as easily as the Mexicans. - I think the presenters deliberately wanted to cause a stink so that they can illustrate how precious, sensitive and ridiculous society is becoming.
I find the "You can't say / think that!" culture far more offensive than any stereotypes spoken in jest, including ones made about my background (which is a good job really as I'm half Scottish
). - If you haven't got the common sense / intelligence to distinguish between a joke and a malicious comment, go and live in a hole somewhere away from the rest of society because you'll never be happy until everything is sterilised , you're wrapped in cotton wool and everyone else is miserable. You're probably the same kind of person that wants every speed limit dropped to 10-mph and alcohol consumption, sex & fun to be outlawed.
If you read some of their books, or look into their lives in more detail, you'll find that all 3 TG presenters are quite enlightened when it comes to history, politics, world affairs etc. and the "racist" gags they make on TV are just a silly bit of fun.