I think the reason why it isn't funny for me is exactly the reason why it's hilarious to other people: I fail to get most of the references.
I have never seen a peep in my life, and while I am familiar with the story of Linvingston, I had no idea who Hoffa was until I looked the name up. I also have no idea what "flaking" means to hippies, and why it is amusing to a passing-by observer. I have to wait until the humour is explained to me by the kind people at these forums, and let's face it - if a joke has to be explained, it won't make you laugh. It will make you go "Oh" insead of "Ooooh! That's just brilliant!"
I wish I could enjoy this comic as much as other people do, but apparently my background prevents me from doing so. Quite sad, really.