Surely you understand that it's somewhat difficult for sites to survive without videogame advertising?
Ain't many companies who make home appliances looking to advertise on videogame sites. Then the second non-gaming companies like Doritos and Mountain Dew DO get involved, look what happens.
I do see the point that you're making, but ruling out sites that have videogame advertising at all is ridiculous. Sites that sell their OWN videogame advertising...now that's a problem. Sites with a third-party ad company doing the selling...fine by me.
That's mainly because the level of discourse in review comments is about the same as your post, as opposed to "I didn't agree with/like this review because of..."
It's usually just "OMG DIS REVIEW IS A JOKE" or "UR ALL SONY FANBOYS FOR GIVING THIs GAME A 9."
Reviews won't improve until the target audience learns to give constructive criticism over and above "I disagree with your opinion so you're a waste of space" which, let's face it, is the what 99% of people with negative opinions of reviews actually mean when they criticise.