Interesting Premise, I don't strictly agree.

The difference or line that I like to draw is that while I may appreciate things cherry picked from other cultures, I don't express that like by adopting it as my own.  Appreciation of a different genera of is not the same as trying to take ownership and combine with other things to make something unique.

The things Portlandia makes fun of really is the most extreme outlandish take on situations that makes them ripe for ridicule.  For instance insisting on meeting the chicken that you are going to eat for dinner.  It's applying absurdism to something the earnest desire to not be so removed from the production of our food.