I have always thought that he meant that mostly as a joke. Note how now it says "The cure for the corporate review" -- kind of a new way of saying the same thing. It's probably part dig at the questionable quality of a lot of professional game reviewing, too... not sure on that point though.
However, Mark has been doing internet game reviews on and off since 1999. First person on the internet to do a video review show, apparently... or at least that's what he's said before on the show. Even if you are absolutely right that he doesn't research the games he's reviewing enough and thus often doesn't mention a lot of important information, he's been doing this for a long time, and that's got to be a "journalistic" qualification of some kind for sure!