This has all been discussed at length in the Games Journalism thread with lots and lots of industry insiders giving their opinions in that thread. The OP has been constantly updated with highlighted links to posts by prominent people in the industry. I highly suggest checking it out. I think it is one of the best threads I have ever seen from this community. For now, I am just going to give a quote from o e of Jeff Green's posts because I think he does a great job addressing this particular point. I will refrain from bolding the whole thing:
but the quote you are showing is exactly what they are doing: klepec did it in his column, jeff did it in the thread you highlighted, they said it on the podcast and brad said it here.
they are aware that they are bombarded by PR and they are aware that they are human. which is why there are gray zones and there always will be. Either we trust the GB guys to handle those gray zones to our benefit or we don't.
There is no site where we see more about the review process and hear more about the thoughts of the reviewers who write them. They have been very transparent about this stuff for years and openly mocked poor attemtps at PR that most video sites simply ignored. They've also been more open about their relationships with PR people than any other site i know. I value that a lot more than a piece of paper with ethical guidelines as reaction from sudden internet outrage.
Polygon had that too, we saw how much water these hold. Actions are better than words in this case and GB has been a lot better at handling these issues since their inception than most other sites imo.