Is Schuld that bad? I haven't played it yet, though I've played Desert Nightmare, which is by the same author. I thought Desert Nightmare was a decent game, though nothing amazing.
As for the list itself, I think it's alright, though I get the feeling they probably didn't do a whole lot of research in making the list. I kind of wonder how they defined "games of 2013", since most of these were made in 2012 or earlier, but only got an English translation or post-completion version update in 2013, and some, like Yume Nikki didn't even get that. Of that list, only Skinwalker, Mad Father and maybe The Crooked Man (can't find a Japanese release date for that one) were made in 2013.
Perhaps it would've been better to make it a "Best RPG Maker Horror Games" list; I know I'd have liked to see Corpse Party, Lisa, or OFF on that list, though none of those were made in 2013 either.