Its not "enjoyable" in the sense that it is "entertaining" at all. It just lends itself to the fact that all too often a bully gets away with everything and never gets his due. Well not only did he get what was due him but from someone that you would never expect. It was to me a 100% "Wow" factor more than anything else. Hope that helps.
I think the Mortal Kombat one was just trying to capitalize on stupidity and was just unnecessary. But hey thats just me.