The man has been a game critic for almost as long as I have been alive.
I challenge anyone to maintain high levels of enthusiasm for decades about your hobby, especially if picking apart that hobby turns into your job.
His years of experience makes him invaluable for game reviews. If you want someone to review the game who is more in line with your own tastes, that's fine (although I don't really get the point, if you already like the game there's no reason a review should matter to you at all), but if you want a genuine, and by this stage expert critical eye on it, Jeff is the man to do so.
I went to a Pearl Jam gig a few years back to write a review of the gig for a magazine. The reason they asked me to do it (I don't even work there), was because I am a big Pearl Jam fan and there was no one on staff who was. I went along happily, and wrote a glowing review (I never had a chance to see them years back, it was my first time). I submitted the review, they were happy, and there was some nice comments on the article.
It was only after reading it in work that I thought "Well what the fuck was the point of doing it in the first place?"
I have no idea what possible use anyone got out of it. EDIT - Other than those who missed the gig getting confirmation that the band they like are still great.