From what I understand, the game review community is somewhat small and not impressively compensated. Game reviewers "win" prizes or go to paid for press events in exchange for positive reviews, and can be fairly vindictive in responding when claims of unethical behavior are leveled their way. In this article Jason asserts that the coverage of games is for the consumer, but when writers preemptively release 8/10 reviews for games that are essentially broken on release, I would say it is fairly clear that the coverage most serves the purposes of the game publishers and reporters.

This is an old story, and ever time it comes up I am reminded of Roger Ebert's little book of rules:

Be wary of freebies. The critic should ideally never accept round-trip first-class air transportation, a luxury hotel room, a limo to a screening and a buffet of chilled shrimp and cute little hamburgers in preparation for viewing a movie. If you go, your employer should pay for the trip. I understand some critics work for places that won't even pick up the cost of a movie ticket, and are so underpaid they have never tasted a chilled shrimp. Others work for themselves, an employer who is always going out of business. Yet they are ordered to produce a piece about Michael Cera's new film. I cut them some slack. Let them take the junket. They need the food. Also, I admire Michael Cera. But if they work for a place that is filthy rich, they should turn down freebies.

The whole article is a great read, a real insight into the practical application of ethics, and also has some bits about rice cookers, because it's Roger Ebert, the man who wrote a cook book entirely about rice cookers.

Seriously.