I debated on writing this as this is a humour section
My wife is blonde and I showed her the joke last night, she cracked up. She is extremely bright. The term political correctness is used to describe the avoidance of language or actions that are seen as excluding, marginalizing, or insulting groups of people who are seen as disadvantaged or discriminated against, especially groups defined by sex or race. I don't see blondes as a group being discriminated against. We have put political correctness above common sense. The politically correct line keeps getting moved every day with someone being overly sensitive to humour, language, looks etc. As long as these things are not directed at someone specificity, or hurtful to a group, Please start looking at it as a what it was intended, as a funny joke. Taking offence to that joke is a depressing thought. Soon with the line moving more and more, I think we may not be able to communicate with each other at all.
Having said that, this is my opinion and the well known member from Pittsburgh has the right to his.