I need to disagree here, what good is a review section if you can only post certain kinds of views about the product? What would the intended use be? I personally think the downfall of review sections in general is the score system. I believe the score systems sort of undermine the reviews themselves. Yet, I obviously understand why they are used and that they are 'useful' for people.
That's true, but very often review systems are not designed for bombings and fall apart there.
The best design I see for this is something like Steam, which has "recent" and "overall" reviews, which are more resistant to bombings but also allow them. If the publisher screws people on a DLC or IAP, people would want to know, but in some cases, it's just emotional exaggeration led by someone else.