OK, so here's the thing... 
A bunch of trolls got upset because someone added a cartoon reference to the wood article and well this is a wood article "not a cartoon article".  That's mildly valid.  Well, it's not a sculpture article either, yet there's a sculpture on the first paragraph.  That's allowed because wood is used in the sculpture.  Well, wood is used in that comic now and that's every bit as real.  The only difference is some boring person came upon the duck sculpture by accident, and the XKCD reference brought itself into relevance on its own.  If anything this makes the XKCD reference more relevant, not less than a sculpture of two birds.  The only difference is that you're jealous you didn't think of it yourself first.  Reality is reality because it is real not because it stays in a Wikipedia article without being censored.  XKCD is real.  Wikipedia generates content, but how narcissistic would one have to be to think Wikipedia is the only place that can.  Wikipedia exists to accurately document the world.  XKCD is a part of that, certainly more important and interesting than wood.  XKCD is popular culture, and anything less than an acknowledgment of that would be a direct offense to it's author, Randal Munroe, and his truly inspiring gift to this Earth.  You should think first before brushing off something so grand.  If wood wasn't in popular culture yet, is sure as heck is now, and you have the Wiki-censors to thank for that.