To be fair, and attempt to be unbiased; the article linked by the OP isn't a sufficient argument in defense for violent video games not being taxed. He seems to use ad hominem to distort the character of the one he is trying to prove wrong (making the debate about the author of the argument, rather than the argument itself) and ultimately, his big argument seems to be that comic books had the same criticism 60 years ago, and that Japan has a much less crime rate, though, he doesn't provide us with anything to support such an idea isn't linked to something else culturally, and finally, similarity doesn't equal relation, so the argument isn't truth preserving.
My opinion. Violent video games already have parental guidelines, and if a parents deems it right that their child can put such a thing into their mind, maybe even shaping their conscience, then the debate is about parenting, not the video game industry.