Gamespot underrating games?

Lately, I've seen low Gamespot reviews for highly anticipated games. Games like Bioshock which everyone hyped to be 9.5 and it got 9.0 although it's still AAA. But remember that this game got high reviews from all sites! (9.7-10)

Now for the worse, Metroid Prime 3 : Corruption got a 8.5! How stupid is that considering the first two games are AAA (9.7,9.1 respectively) This game, like Bioshock is way more underrated because it got high reviews everywhere too! I think it should get at least 9.0!

Is it me or Gamespot has became way more harsh in their reviews? If this trend continues, I can't see any PS3 game scores AAA at Gamespot.

As a side note,
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