If you think Cataclysm is worse than WotLK, it doesn't instantly mean you hate Cataclysm so much that you won't be playing. If I say something random like ''Donkey Kong Country 2 was better than 1!'' it doesn't mean I won't play DKC1.
I can understand why GameSpot gave a lower score, people use your minds, they are looking at what the expansion pack themselves bring.
This means: 1-60 new content is NOT included, they are free, so GameSpot is not looking at it for its rating
New talents also NOT included, they didn't come with the expansion pack
Guild leveling, also NOT included as far as I know
And probably a lot more not coming with the expansion pack
What we do get from the pack is:
- 5 new zones
- 9 new dungeons
- 4 new raids
- level cap increased to 85
- new battlegrounds
- archeology
- worgen and goblin
- maybe more that I forgot
So my last list is pretty much where Gamepot is looking at to rate the game, and if you look closely, its just what TBC and WotLK gave us also, just a lot less.