No. If you got a 5/10 on a test at school, would you have been happy?
Of course not. It doesn't change the fact that anything between 40 and 60% is average - see normal distribution. On a scale from 1 to 100, scores above 90 should be rare and scores ~50 common. If it's any different, there's something wrong with the ratings - and in fact this is the situation we're dealing with today, when reviewers dread to rate a well-known developer any lower than 80 even if the game is mediocre.
There's nothing wrong with average. Some games are terrible, some are outstanding, most of them fall in between. It should be reflected in the ratings. Yes, Bethesda can't be satisfied with a 6/10 score - then again, players are not entirely satisfied with Dawnguard either, so maybe the score is not so far-fetched.