Well for me Demon's and Dark Souls is more about the atmosphere and setting than the gameplay. The gameplay is okay and it really isn't as hard as people want to believe it is. There is something to be said about minimalistic story approach, I love it. I loved the King's Field games back in the day, some of my favorite and it most certainly wasn't because of the gameplay (which is surprisingly like Skyrim LOL). Anyway, not explaining the entire reason for being and having a pretty surreal set of characters and locations takes more effort than you may think. I personally think from a story telling perspective (to me the best stories of all times are open for different interpretations) is the reason any Souls game deserves the praise it gets.
People point them out and say "Game of the generation"...What? I don't have a problem with you liking the game but some...fanboys go "every RPG needs to be like Demon and Dark Souls and if they aren't then you are just butthurt" Dark Souls was boring beyond boring for me. One of THE worst purchases I've made this gen.
It's not overrated. It just seems that way because the fanboys are much more vocal than most people --- I disapprove of what you say, but I will defend to the death your right to say it