I guess I can agree to a point, since I think a lot of the time I can tell a good game from a bad one as well, even if it's a little outside my sphere of influence, but I don't think that's nearly reliable enough to be called journalism, no offense to your personal method. Reviews are subjective enough as it is, being merely opinion pieces that interpret facts as much as they present them, and moving any further away from objectivity to me is simply dangerous.
Dominic above I think demonstrates this pretty well when he says he can acknowledge that a game outside his scope is good, but he still doesn't think he'd be the man to review it.