Reviews inform people of the games quality though, and there is a MASSIVE difference between a sport and a game in the way you're trying to present it.
People knew Michael Jordan was good because he played great his entire career, and BY THE TIME he was making all his money there was no question about his skill. A game however can be hit and miss for even seasoned developers and people don't know of its quality and therefore are not willing to pay the money till they know. Reviews therefore give them this insight, it could be related to a highlight package for a college star about to be drafted into the NBA, etc.
People knew that Michael Jordan was good by his first season. They knew this by watching him play and not going just off the comments of sports writers.
A game's potential is built on hype, marketing and actual quality and not reviews. Every game that has sold well this generation was a known entity and well hyped well before release. Also, preorders coorelate nicely with sales.
Reviews highlight great games and act as an added incentive to purchase, but you can't significantly manufacture high volume of sales by just having a bunch of review sites give a game a bunch 9s and 9.5s especially one that obviously doesn't deserve those scores.
Publishers influence on games scores has been apparent for some time but there are natural counterbalances to such influences that have led to very obvious percularities (spelling off but I being lazy right now) of the general gaming review system.
If you asked me to judge anything in life besides a game on a 10 point scale and I gave you a 5, you would probably take score as meaning "average". However, a 5 out 10 score from any gaming review site typically means "garbage" to the average gamer. Gaming site that are overly generous with highscores are the ones that are taken less seriously be gamers. There is a reason that metacritic and gamerankings have gain such prevalence in the gaming world. Plus, reviewers don't have short term memories and if they were influenced to give a certain game a fluffed up score then they are more likely to score better games higher. In essense both gamers and actual review writers have lessen the effect of a publishers influence on scores.
Publishers haven't broke the scoring system, it just thier influence plus counterbalances instituted by review writers and gamers have indiretly forced gaming websites to make a 4 point scale look like a 10 point scale, where games typically score between 7 and 10, and 6.9 and below represent no man's land.