So I've been thinking about Stephen King's On Writing, more specifically his thoughts on how plots can be "labored and artificial". I was thinking that's why agents like high concept books, because it focuses on characters, which is also what readers like the most and can relate to. And while I think Stephen King is right about that, I still find myself liking plotted books. I fall in love with characters, but if there isn't something pushing them forward, I kind of stall. Maybe those specific books I read weren't character-driven enough, but either way I still find myself liking books with plots. I do like what he stated about putting characters in a situation and seeing how they get themselves out of it, though he says that's not a "plot".
I have to remember that there are no hard-and-fast rules (except for maybe spelling and grammar, but even those can be stretched) and it's something that I forget a lot. These are King's suggestions, which are really good suggestions, but they won't work for every story. I think maybe for my next book I will throw characters into a predicament and see them work themselves out of it. But for now, I need to focus on making my books the best they can be and not take his word as Rule.