It works both ways, but there are more unjustified low scores than higher ones. After actually playing some of the 7s and 6s, I can say this for a fact.
The Order and Dying Light are the two most recent victims of this, though the user community seems to be redeeming both luckily. However on the flip side, Evolve recieves a suprising amounts of praise from critics. Some games like Infamous and Sunset Overdrive it becomes a wash and averages out fairly, but it is leaning to one extreme or the other way too often. Reviewers these days are a joke for the most part, and this is coming from a former game reviewer. To be honest, with shareplay and twitch, reviews are becoming more pointless these days which may aid in recent behavior. Reviews are a dying breed and as they continue to try to please devs or release clickbait articles, they are speeding up the process. As they are revealed untrustworthy, less people visit their website. They are focusing too much on the short term and not enough on the long term.
I feel bad for the honest ones, and while this kind of practice has been around for a while, it is good that it is being acknowledged by the community as it is not fair to the devs to lose sales over hack reviews.