It's pretty much why I don't pay attention to reviews.
Professional reviewers tend to be bought off, and fan based reviews tend to be fanboys (in one direction or another).
I find a demo, and if one doesn't exist, my friends know which styles of games I like, and which ones I dislike.
Tend to be bought off? Hardly. Sure a few have had issues. By your logic all congressman "tend" to be bought off, all priest "tend" to rape little boys, and all LA cops "tend" to be racist.