I think I was put off of Dark Souls because it was advertised as being very hard. When I think "very hard" I think of obscene shoot'em ups and abusive platformers. These are not my kind of games.
Dark Souls isn't exactly my kind of game either. First of all, I pretty much don't use controllers and I'm under the impression you really want one for Dark Souls. Secondly, there is some kind of multi-player thing where other people can come into your game and kill you - that doesn't appeal to me in the slightest.
What really does appeal to me about Dark Souls is that is looks like one of the coolest exploration games I've seen in a long time. Both in terms of the world and the game mechanics, it seems like there is just a lot to see and do.
Something that seems incredibly sweet about it is that you can just wonder into various boss fights long before you are ready for them. In some cases you can just run right through the boss room, avoiding the fight, and then carry on to another area. There are a ton of different weapons which certainly do different amounts of damage but they also have different ranges, speeds and attack types, so choosing them is more about choosing the one with the highest damage. There appear to be a bunch of different builds you can do depending on which weapons you prefer.
Running around and checking things out is cool. Games that are hard enough to make you feel like you accomplished something when you win are cool. At this point I'm obviously not going to pay full price for it, but if I end up getting it on a deep sale and liking it then I might pay full price for Dark Souls 3, which is obviously going to be a thing.