Just to add my twopenneth. I certainly don't think the drinks are an essential part of the review, pubs exist for lots of different preferences, we just happen to have a predominance of real ale'rs doing most of the good work. But food and just generally being a social hub are key points for some pubs and I think just as valid.
Also even fairly brief reviews tend to act to seed the pub, people feel more comfortable reviewing pubs where a review is already there.
For me the key points of a review are that they are polite and honest. And anyone who has followed my moanings on the forum will know the other one is that a reviewer should always leave a predominance of good reviews. I don't want to read various strops about how rubbish so and so a pub is when I have no idea what they think a good pub is, for me you have to earn the right to tell me which pubs are rubbish. As ROB pointed out on a recent thread the classic review line of "this used to be a really good pub...." - well why didn't you review it then?