First off...that is only 7 reviews and doesn't include an 8.9 that it got from some reviewer that was posted on here
Secondly, all the reviews basically say the same thing, a good/very good/great game that is hampered by very bad technical issues and the score would be a lot higher if not for them. (some of them even saying they will change their review once the issues are fixed)
Lastly, it still had a 210k opening in NA (not including PSN downloads)