This is satire, and is a direct response to how several art critics have dismissed "games" as capable of being considered fine art for reasons that are just as silly as this blog post, which is precisely why it's funny.
The "[x] isn't art" op-ed seems to be that particular Guardian blogger's specialty. Last year, he caused a flurry of outraged discussion in a different set of communities for roughly similar reasons, when he wrote an op-ed on why neither cuisine nor high fashion are art: http://www.guardian.co.uk/artanddesign/jonathanjonesblog/201...