I won't talk about the review or the game, but...
I *strongly* disagree on the idea that a review has "to represent the gaming communities best interest".
A review is / should be EXACTLY a "one person's opinion". An honest one, but still something personnal. As soon as you try to put you in other people shoes, it become nonsense and is useless. I'm FAR more interested in "one person's opinion" (and I'll read many of those) than in a virtual opinion that the writer think should be an 'average gamer' take on a game.
I don't agree with that. If you're a journalist you have a responsibility. Your personal opinion may affect other people decisions.
You can't do a really negative review because you just don't like the game. If you do that you're not better than the average blogger (even if you're more polite). You need to keep your mind cold and try to empathise with your audience. Niche =/= Bad.
A core oriented game like Souls shouldn't get a bad review because X or Y reviewer don't like it. You must know what it is, what people expects and try to do a good job informing about how the game is. If you hate it and you're not able to get into the game for whatever reason and you're going to give a too biased review, ask for an exchange to some of your coworkers.
It's obvious you can't go full objective with a review. Not asking it. But there should be a big difference between a LTTP on GAF and a professional review. That may not be the case here, not saying it is. I haven't played, followed, or have any interest in the game so I can't give a solid opinion about it. But as a general opinion, mine is what I've written above.
When you write in media, you're not only giving your opinion, you're providing a service to your audience. And I think that's an important factor.
That letter looks like a rant because somebody hurt his ego though.