I definitely love this game, but I wish the VT Massacre card wasn't in there. It's not exactly funny for someone who attended the school at the time and lost friends (like myself). I suppose there are similar arguments for a lot of the cards, but the article itself recognizes that one card is particularly rough; the first time the guys played they initially didn't want to include that one.
I suppose the question really is whether everything is acceptable if the goal is to be offensive, right? What if there were racial slurs on the cards? Is that still in good fun? I mean, I personally don't get offended by much, and of course, when I play the game, I just don't use that card.
I really do support this game, and recommend it to all my friends (who have a good sense of humor) but to me it does kind of bring up a broader discussion of whether or not there are some things we objectively shouldn't laugh about, even in a wacky context.