I'll explain why I think DS is not a 'good' game.
Before I do, I'll start listing the positives to put my view in context: It's got a fantastic atmosphere, quality visuals and concepts inspired from other great games, books, and films, and the fighting is complex, deep, and challenging. If that's all you've read so far, then by definition DS is a very good game.
However, what surrounds the core of DS's gameplay are the game maker's version Emperor's New Clothes: The hidden convents, spells, and gear. For the people who don't know they are, these are majority of the most powerful items and empowerments can only be acquired if you go through the game in a specific order. And when I say a specific order, I mean that there is only one or two way of playing through this game to get it.
I know, some people will say that is precisely why DS is great - that there are hidden secrets for players to explore. But this rational is actually false. The idea of exploration is there, but it's the exact opposite in practice. Let me give you an example without spoilers: I made a game, and in this game, I created a powerful ring, and you can only get it if these conditions are met: 1) You've talked to an old lady NPC hidden underneath a bridge that is very hard to land on, 2) You have to talk to her 3 times before completing the 5th mission, 3) You having a morality rating of -120 and 4) You have killed her daughter with a LVL2 Axe of Lolcat.
The reason why the above is not honest exploration is that people who defend DS fail to add a very critical aspect to gaming these days: people talk when they're not playing games. In other words, no matter how deep you bury an item, someone somewhere will eventually find it and post it on the internet for everyone to see. It would be ok if it were an easter egg, and the item is not that powerful. But in DS, these are items are very much THE most vital items to be even marginally successful, especially in a game where PvP is at its core.
So what happens is that while the visuals, the gameplay are great, you have to spend most of your time actually NOT enjoying them and metagame the entire thing. A class called 'Wanderer' is longer chosen because you want to role-play a lone-wolf character, but because you've spent a lot of time prior to playing it by reading the wikis and forums about its build. Yes, you can do that with other games too, but other games are still accessible even if you decide to go pure. But the way DS is structured - by placing key items so buried that is it impractical for even the most dedicated players to discover by themself, given that they constantly face 12-year olds with OP gear they've acquire from wikis and YouTube - it oversteps the fourth wall to the point that all the meaning 'weapons' and 'gear' and 'role play' are meaningless. People don't choose a specific sword or a spell because it suits their fantasy, they choose them only for their utility. Good games are usually balanced between wanting to look good (for role-playing, because that's what made you play it in the first place, ie; you wanted to be a stealth archer within the game's world) and utility (ie, you want to perform the best in actual gameplay), but DS completely makes you toss away the former after a certain point.
Now, in the example with the old lady under the bridge, if I were to reward (and maybe punish) players with items that eventually are powerful for any given scenario, then this become meaningful decision making for players, and therefore the exploration becomes actually meaningful. You are not required to read wikis to find out what you're missing because you'll aways get some feedback.
DS has great gameplay, but it has a few faulty notion of the word 'challenge' that makes the game obnoxious, tricks players into a false sense of it, and takes away initial the point of attraction. I would call it a somewhat interesting but unintended social experiment, where the 'Dark' part of the game is actually encouraging players to be at their darkest to themselves.
