Lol, that is the most ridiculous rationalization I have yet heard. (Could this be the product of a mind soaked too long in "zen" thought?)I think this is how guys show love for one another. Remember when you liked a chick in second grade, you might have punched her or made her cry by saying something mean. Well we kinda did the same thing with guys that we get along with real well. I do think alot of it is comic relief, but I also think part of it comes from our subconsious machismo, it is our way of expressing we actually like one another without feeling all "homo" as some might call it.
There are basically two reasons why guys try to downplay what is simply old-fashioned male competition:
(1) They are on the receiving end of it but admitting that they are losing is too difficult, so -- with delightful irony -- they accuse the other party of being "insecure"; or
(2) They are on the dishing out end but they don't like to think of themselves as nasty or meanspirited so they characterise it as "just playing".